Clarify Buck's behavior with first order dependencies
Clarify Buck's behavior with first order dependencies

Summary:
There exists some confusion (such as Issue #131) about how Buck handles
dependencies.  This change attempts to make it a bit more clear.

In the future, we'll probably want to go further and make a template for
`deps` to include some text about this for every rule.

Test Plan: `./soyweb-local.sh`

lukw00/buck,lukw00/buck,k21/buck,Dominator008/buck,zhan-xiong/buck,shs96c/buck,brettwooldridge/buck,liuyang-li/buck,stuhood/buck,marcinkwiatkowski/buck,vschs007/buck,mikekap/buck,SeleniumHQ/buck,artiya4u/buck,davido/buck,neonichu/buck,stuhood/buck,sdwilsh/buck,daedric/buck,mnuessler/buck,siddhartharay007/buck,1yvT0s/buck,robbertvanginkel/buck,romanoid/buck,marcinkwiatkowski/buck,zhuxiaohao/buck,Addepar/buck,davido/buck,siddhartharay007/buck,zhuxiaohao/buck,tgummerer/buck,mnuessler/buck,illicitonion/buck,Addepar/buck,justinmuller/buck,rowillia/buck,rowillia/buck,dsyang/buck,JoelMarcey/buck,zhan-xiong/buck,JoelMarcey/buck,daedric/buck,justinmuller/buck,rhencke/buck,shs96c/buck,davido/buck,daedric/buck,siddhartharay007/buck,bocon13/buck,luiseduardohdbackup/buck,mikekap/buck,raviagarwal7/buck,daedric/buck,SeleniumHQ/buck,sdwilsh/buck,rmaz/buck,zhan-xiong/buck,nguyentruongtho/buck,OkBuilds/buck,mnuessler/buck,Distrotech/buck,justinmuller/buck,grumpyjames/buck,zhuxiaohao/buck,rowillia/buck,kageiit/buck,neonichu/buck,robbertvanginkel/buck,grumpyjames/buck,davido/buck,janicduplessis/buck,romanoid/buck,OkBuilds/buck,mikekap/buck,tgummerer/buck,shs96c/buck,Addepar/buck,liuyang-li/buck,justinmuller/buck,pwz3n0/buck,neonichu/buck,marcinkwiatkowski/buck,justinmuller/buck,siddhartharay007/buck,brettwooldridge/buck,siddhartharay007/buck,siddhartharay007/buck,brettwooldridge/buck,robbertvanginkel/buck,Learn-Android-app/buck,raviagarwal7/buck,Addepar/buck,LegNeato/buck,mread/buck,1yvT0s/buck,Addepar/buck,saleeh93/buck-cutom,darkforestzero/buck,raviagarwal7/buck,dushmis/buck,dpursehouse/buck,raviagarwal7/buck,kageiit/buck,dushmis/buck,nguyentruongtho/buck,zhan-xiong/buck,stuhood/buck,Distrotech/buck,tgummerer/buck,lukw00/buck,mogers/buck,grumpyjames/buck,dushmis/buck,Addepar/buck,mnuessler/buck,darkforestzero/buck,mread/buck,rhencke/buck,rhencke/buck,dushmis/buck,Heart2009/buck,kageiit/buck,raviagarwal7/buck,darkforestzero/buck,Dominator008/buck,pwz3n0/buck,romanoid/buck,LegNeato/buck,Learn-Android-app/buck,SeleniumHQ/buck,liuyang-li/buck,bocon13/buck,rhencke/buck,Addepar/buck,shybovycha/buck,OkBuilds/buck,neonichu/buck,stuhood/buck,LegNeato/buck,shybovycha/buck,dsyang/buck,Addepar/buck,stuhood/buck,lukw00/buck,dushmis/buck,clonetwin26/buck,clonetwin26/buck,janicduplessis/buck,rhencke/buck,luiseduardohdbackup/buck,grumpyjames/buck,Distrotech/buck,Addepar/buck,pwz3n0/buck,OkBuilds/buck,Distrotech/buck,MarkRunWu/buck,OkBuilds/buck,dsyang/buck,clonetwin26/buck,justinmuller/buck,mogers/buck,luiseduardohdbackup/buck,janicduplessis/buck,zhan-xiong/buck,rmaz/buck,OkBuilds/buck,sdwilsh/buck,mikekap/buck,vine/buck,JoelMarcey/buck,mread/buck,nguyentruongtho/buck,brettwooldridge/buck,Dominator008/buck,MarkRunWu/buck,Addepar/buck,mogers/buck,1yvT0s/buck,rowillia/buck,justinmuller/buck,illicitonion/buck,daedric/buck,vschs007/buck,neonichu/buck,janicduplessis/buck,artiya4u/buck,vschs007/buck,SeleniumHQ/buck,tgummerer/buck,vschs007/buck,neonichu/buck,marcinkwiatkowski/buck,OkBuilds/buck,1yvT0s/buck,shybovycha/buck,artiya4u/buck,JoelMarcey/buck,grumpyjames/buck,dpursehouse/buck,vschs007/buck,zhuxiaohao/buck,rmaz/buck,facebook/buck,Learn-Android-app/buck,SeleniumHQ/buck,artiya4u/buck,rowillia/buck,liuyang-li/buck,illicitonion/buck,SeleniumHQ/buck,liuyang-li/buck,dsyang/buck,ilya-klyuchnikov/buck,davido/buck,liuyang-li/buck,facebook/buck,bocon13/buck,1yvT0s/buck,rowillia/buck,Distrotech/buck,justinmuller/buck,siddhartharay007/buck,LegNeato/buck,dsyang/buck,LegNeato/buck,romanoid/buck,artiya4u/buck,SeleniumHQ/buck,mread/buck,neonichu/buck,brettwooldridge/buck,grumpyjames/buck,Distrotech/buck,Distrotech/buck,Heart2009/buck,marcinkwiatkowski/buck,luiseduardohdbackup/buck,Distrotech/buck,darkforestzero/buck,zpao/buck,hgl888/buck,Heart2009/buck,rhencke/buck,JoelMarcey/buck,hgl888/buck,romanoid/buck,zhuxiaohao/buck,k21/buck,raviagarwal7/buck,marcinkwiatkowski/buck,mread/buck,romanoid/buck,artiya4u/buck,luiseduardohdbackup/buck,mogers/buck,dpursehouse/buck,robbertvanginkel/buck,shybovycha/buck,Dominator008/buck,grumpyjames/buck,liuyang-li/buck,brettwooldridge/buck,dushmis/buck,stuhood/buck,Addepar/buck,ilya-klyuchnikov/buck,LegNeato/buck,LegNeato/buck,shybovycha/buck,zhuxiaohao/buck,SeleniumHQ/buck,janicduplessis/buck,Heart2009/buck,shs96c/buck,mikekap/buck,lukw00/buck,daedric/buck,zpao/buck,ilya-klyuchnikov/buck,Learn-Android-app/buck,hgl888/buck,bocon13/buck,rowillia/buck,raviagarwal7/buck,shybovycha/buck,rowillia/buck,vine/buck,SeleniumHQ/buck,mogers/buck,Learn-Android-app/buck,dsyang/buck,daedric/buck,dsyang/buck,brettwooldridge/buck,dpursehouse/buck,janicduplessis/buck,illicitonion/buck,vine/buck,1yvT0s/buck,Heart2009/buck,dpursehouse/buck,LegNeato/buck,robbertvanginkel/buck,dsyang/buck,LegNeato/buck,brettwooldridge/buck,Distrotech/buck,zhan-xiong/buck,kageiit/buck,mnuessler/buck,marcinkwiatkowski/buck,daedric/buck,neonichu/buck,Learn-Android-app/buck,Addepar/buck,LegNeato/buck,rowillia/buck,artiya4u/buck,LegNeato/buck,mikekap/buck,lukw00/buck,janicduplessis/buck,facebook/buck,mikekap/buck,clonetwin26/buck,daedric/buck,liuyang-li/buck,OkBuilds/buck,luiseduardohdbackup/buck,rhencke/buck,kageiit/buck,tgummerer/buck,liuyang-li/buck,k21/buck,pwz3n0/buck,MarkRunWu/buck,JoelMarcey/buck,vschs007/buck,zhuxiaohao/buck,illicitonion/buck,marcinkwiatkowski/buck,mnuessler/buck,ilya-klyuchnikov/buck,illicitonion/buck,k21/buck,vine/buck,darkforestzero/buck,brettwooldridge/buck,tgummerer/buck,JoelMarcey/buck,luiseduardohdbackup/buck,luiseduardohdbackup/buck,stuhood/buck,ilya-klyuchnikov/buck,tgummerer/buck,zpao/buck,Addepar/buck,romanoid/buck,SeleniumHQ/buck,davido/buck,clonetwin26/buck,Learn-Android-app/buck,grumpyjames/buck,liuyang-li/buck,shybovycha/buck,mogers/buck,1yvT0s/buck,bocon13/buck,nguyentruongtho/buck,rmaz/buck,marcinkwiatkowski/buck,Dominator008/buck,pwz3n0/buck,Dominator008/buck,dushmis/buck,rhencke/buck,sdwilsh/buck,JoelMarcey/buck,facebook/buck,clonetwin26/buck,justinmuller/buck,siddhartharay007/buck,mogers/buck,SeleniumHQ/buck,Dominator008/buck,rowillia/buck,robbertvanginkel/buck,romanoid/buck,ilya-klyuchnikov/buck,k21/buck,clonetwin26/buck,shybovycha/buck,vschs007/buck,shybovycha/buck,dsyang/buck,bocon13/buck,janicduplessis/buck,kageiit/buck,artiya4u/buck,zpao/buck,brettwooldridge/buck,robbertvanginkel/buck,zhan-xiong/buck,romanoid/buck,vschs007/buck,k21/buck,vschs007/buck,mnuessler/buck,grumpyjames/buck,artiya4u/buck,raviagarwal7/buck,mread/buck,shs96c/buck,facebook/buck,davido/buck,lukw00/buck,rmaz/buck,sdwilsh/buck,darkforestzero/buck,nguyentruongtho/buck,illicitonion/buck,stuhood/buck,davido/buck,1yvT0s/buck,mnuessler/buck,daedric/buck,OkBuilds/buck,dsyang/buck,justinmuller/buck,ilya-klyuchnikov/buck,marcinkwiatkowski/buck,raviagarwal7/buck,hgl888/buck,lukw00/buck,MarkRunWu/buck,vine/buck,clonetwin26/buck,1yvT0s/buck,saleeh93/buck-cutom,zhan-xiong/buck,janicduplessis/buck,robbertvanginkel/buck,clonetwin26/buck,Learn-Android-app/buck,marcinkwiatkowski/buck,Learn-Android-app/buck,rhencke/buck,robbertvanginkel/buck,davido/buck,clonetwin26/buck,darkforestzero/buck,robbertvanginkel/buck,rmaz/buck,tgummerer/buck,rowillia/buck,janicduplessis/buck,vine/buck,rhencke/buck,ilya-klyuchnikov/buck,Heart2009/buck,robbertvanginkel/buck,dsyang/buck,bocon13/buck,bocon13/buck,shs96c/buck,mikekap/buck,shs96c/buck,vine/buck,vine/buck,rmaz/buck,rmaz/buck,davido/buck,hgl888/buck,saleeh93/buck-cutom,facebook/buck,Heart2009/buck,raviagarwal7/buck,rhencke/buck,facebook/buck,zhan-xiong/buck,zhan-xiong/buck,dushmis/buck,pwz3n0/buck,kageiit/buck,MarkRunWu/buck,brettwooldridge/buck,darkforestzero/buck,hgl888/buck,darkforestzero/buck,shybovycha/buck,ilya-klyuchnikov/buck,sdwilsh/buck,mikekap/buck,dushmis/buck,pwz3n0/buck,Learn-Android-app/buck,rmaz/buck,davido/buck,brettwooldridge/buck,rmaz/buck,liuyang-li/buck,shybovycha/buck,dpursehouse/buck,k21/buck,JoelMarcey/buck,rmaz/buck,sdwilsh/buck,robbertvanginkel/buck,vine/buck,Distrotech/buck,vschs007/buck,nguyentruongtho/buck,vine/buck,mikekap/buck,raviagarwal7/buck,k21/buck,pwz3n0/buck,mnuessler/buck,shs96c/buck,marcinkwiatkowski/buck,sdwilsh/buck,mikekap/buck,illicitonion/buck,illicitonion/buck,nguyentruongtho/buck,dsyang/buck,stuhood/buck,romanoid/buck,rmaz/buck,ilya-klyuchnikov/buck,zhuxiaohao/buck,vine/buck,davido/buck,lukw00/buck,grumpyjames/buck,clonetwin26/buck,vschs007/buck,bocon13/buck,illicitonion/buck,MarkRunWu/buck,bocon13/buck,darkforestzero/buck,daedric/buck,janicduplessis/buck,JoelMarcey/buck,hgl888/buck,ilya-klyuchnikov/buck,neonichu/buck,SeleniumHQ/buck,Heart2009/buck,tgummerer/buck,clonetwin26/buck,dpursehouse/buck,Dominator008/buck,pwz3n0/buck,SeleniumHQ/buck,siddhartharay007/buck,Dominator008/buck,mikekap/buck,artiya4u/buck,shybovycha/buck,pwz3n0/buck,hgl888/buck,vschs007/buck,saleeh93/buck-cutom,k21/buck,LegNeato/buck,mogers/buck,JoelMarcey/buck,raviagarwal7/buck,mogers/buck,Dominator008/buck,artiya4u/buck,romanoid/buck,bocon13/buck,sdwilsh/buck,romanoid/buck,darkforestzero/buck,romanoid/buck,clonetwin26/buck,OkBuilds/buck,shs96c/buck,zpao/buck,robbertvanginkel/buck,lukw00/buck,OkBuilds/buck,pwz3n0/buck,hgl888/buck,justinmuller/buck,Distrotech/buck,daedric/buck,shs96c/buck,dsyang/buck,k21/buck,sdwilsh/buck,sdwilsh/buck,justinmuller/buck,grumpyjames/buck,ilya-klyuchnikov/buck,saleeh93/buck-cutom,darkforestzero/buck,shs96c/buck,k21/buck,dpursehouse/buck,mogers/buck,tgummerer/buck,shybovycha/buck,shs96c/buck,dushmis/buck,rmaz/buck,lukw00/buck,MarkRunWu/buck,Dominator008/buck,illicitonion/buck,marcinkwiatkowski/buck,saleeh93/buck-cutom,grumpyjames/buck,sdwilsh/buck,luiseduardohdbackup/buck,zhan-xiong/buck,illicitonion/buck,davido/buck,bocon13/buck,rowillia/buck,zhan-xiong/buck,darkforestzero/buck,OkBuilds/buck,JoelMarcey/buck,stuhood/buck,vschs007/buck,brettwooldridge/buck,zhuxiaohao/buck,sdwilsh/buck,Learn-Android-app/buck,zpao/buck,raviagarwal7/buck,LegNeato/buck,ilya-klyuchnikov/buck,OkBuilds/buck,zpao/buck,tgummerer/buck,daedric/buck,MarkRunWu/buck,Dominator008/buck,stuhood/buck,Heart2009/buck,janicduplessis/buck,shs96c/buck,justinmuller/buck,illicitonion/buck,k21/buck,zhan-xiong/buck,mogers/buck,JoelMarcey/buck,k21/buck