hosts/bsd: sort NFS exports to avoid false validation errors [GH-2927]
hosts/bsd: sort NFS exports to avoid false validation errors [GH-2927]

With a synced folder configuration like so:

 synced_folder ".", "/vagrant", :nfs => true
 synced_folder "#{ENV['HOME']}/mirror", "/mirror", :nfs => true
 synced_folder ENV['HOME'], "/home/#{ENV['USER']}", :nfs => true

on OSX, vagrant writes two overlapping exports to /etc/exports
which then fail the export check.

Iterating through the list of folders lexically builds a correct, single
exports entry.

Signed-off-by: Teemu Matilainen <412caac4b75aee80e68ad734fb9021c11d7da9c8@iki.fi>

sax/vagrant,rivy/vagrant,senglin/vagrant,Avira/vagrant,PatOShea/vagrant,tomfanning/vagrant,iNecas/vagrant,tknerr/vagrant,johntron/vagrant,vamegh/vagrant,blueyed/vagrant,sideci-sample/sideci-sample-vagrant,philwrenn/vagrant,obnoxxx/vagrant,aaam/vagrant,justincampbell/vagrant,clinstid/vagrant,sni/vagrant,kamigerami/vagrant,taliesins/vagrant,aaam/vagrant,teotihuacanada/vagrant,lukebakken/vagrant,johntron/vagrant,wkolean/vagrant,dharmab/vagrant,gitebra/vagrant,jmanero/vagrant,Sgoettschkes/vagrant,jfchevrette/vagrant,jberends/vagrant,bheuvel/vagrant,mwrock/vagrant,dhoer/vagrant,benh57/vagrant,MiLk/vagrant,vamegh/vagrant,genome21/vagrant,pwnall/vagrant,tomfanning/vagrant,senglin/vagrant,bdwyertech/vagrant,marxarelli/vagrant,Chhunlong/vagrant,tbarrongh/vagrant,lonniev/vagrant,vamegh/vagrant,marxarelli/vagrant,jberends/vagrant,Avira/vagrant,signed8bit/vagrant,benh57/vagrant,lukebakken/vagrant,denisbr/vagrant,mpoeter/vagrant,jfchevrette/vagrant,ArloL/vagrant,philoserf/vagrant,myrjola/vagrant,gbarberi/vagrant,jhoblitt/vagrant,ianmiell/vagrant,gbarberi/vagrant,theist/vagrant,muhanadra/vagrant,lukebakken/vagrant,wkolean/vagrant,nickryand/vagrant,miguel250/vagrant,lukebakken/vagrant,Chhunlong/vagrant,ianmiell/vagrant,petems/vagrant,aneeshusa/vagrant,lonniev/vagrant,doy/vagrant,tomfanning/vagrant,jtopper/vagrant,kamazee/vagrant,denisbr/vagrant,mpoeter/vagrant,myrjola/vagrant,Chhed13/vagrant,mwarren/vagrant,gbarberi/vagrant,channui/vagrant,tschortsch/vagrant,channui/vagrant,jean/vagrant,petems/vagrant,myrjola/vagrant,marxarelli/vagrant,kamigerami/vagrant,Sgoettschkes/vagrant,Endika/vagrant,tbarrongh/vagrant,janek-warchol/vagrant,aaam/vagrant,jhoblitt/vagrant,wangfakang/vagrant,invernizzi-at-google/vagrant,kamazee/vagrant,apertoso/vagrant,carlosefr/vagrant,theist/vagrant,jmanero/vagrant,ianmiell/vagrant,rivy/vagrant,Chhunlong/vagrant,miguel250/vagrant,darkn3rd/vagrant,justincampbell/vagrant,tjanez/vagrant,mwarren/vagrant,gajdaw/vagrant,dhoer/vagrant,PatOShea/vagrant,bheuvel/vagrant,invernizzi-at-google/vagrant,jtopper/vagrant,patrys/vagrant,bheuvel/vagrant,PatOShea/vagrant,darkn3rd/vagrant,wkolean/vagrant,Chhed13/vagrant,gitebra/vagrant,mkuzmin/vagrant,benh57/vagrant,tbriggs-curse/vagrant,loren-osborn/vagrant,dhoer/vagrant,blueyed/vagrant,ferventcoder/vagrant,legal90/vagrant,jkburges/vagrant,fnewberg/vagrant,bshurts/vagrant,theist/vagrant,shtouff/vagrant,Endika/vagrant,tjanez/vagrant,stephancom/vagrant,krig/vagrant,Sgoettschkes/vagrant,justincampbell/vagrant,bdwyertech/vagrant,lonniev/vagrant,ferventcoder/vagrant,jhoblitt/vagrant,dustymabe/vagrant,invernizzi-at-google/vagrant,mitchellh/vagrant,blueyed/vagrant,chrisvire/vagrant,BlakeMesdag/vagrant,bshurts/vagrant,ferventcoder/vagrant,PatrickLang/vagrant,tknerr/vagrant,justincampbell/vagrant,TheBigBear/vagrant,jberends/vagrant,gitebra/vagrant,tknerr/vagrant,wkolean/vagrant,kamigerami/vagrant,Sgoettschkes/vagrant,loren-osborn/vagrant,Avira/vagrant,mpoeter/vagrant,ianmiell/vagrant,dustymabe/vagrant,jean/vagrant,carlosefr/vagrant,krig/vagrant,kalabiyau/vagrant,obnoxxx/vagrant,dustymabe/vagrant,marxarelli/vagrant,denisbr/vagrant,cgvarela/vagrant,PatrickLang/vagrant,senglin/vagrant,apertoso/vagrant,stephancom/vagrant,kalabiyau/vagrant,tbriggs-curse/vagrant,tschortsch/vagrant,sideci-sample/sideci-sample-vagrant,BlakeMesdag/vagrant,iNecas/vagrant,TheBigBear/vagrant,myrjola/vagrant,patrys/vagrant,jkburges/vagrant,wangfakang/vagrant,rivy/vagrant,apertoso/vagrant,kalabiyau/vagrant,otagi/vagrant,kamazee/vagrant,chrisroberts/vagrant,kamazee/vagrant,dharmab/vagrant,muhanadra/vagrant,legal90/vagrant,tbarrongh/vagrant,clinstid/vagrant,miguel250/vagrant,krig/vagrant,muhanadra/vagrant,senglin/vagrant,krig/vagrant,dhoer/vagrant,jmanero/vagrant,jean/vagrant,gpkfr/vagrant,mwarren/vagrant,tschortsch/vagrant,kalabiyau/vagrant,miguel250/vagrant,pwnall/vagrant,h4ck3rm1k3/vagrant,ArloL/vagrant,gpkfr/vagrant,gpkfr/vagrant,fnewberg/vagrant,MiLk/vagrant,chrisvire/vagrant,muhanadra/vagrant,patrys/vagrant,invernizzi-at-google/vagrant,tjanez/vagrant,doy/vagrant,aneeshusa/vagrant,shtouff/vagrant,shtouff/vagrant,chrisroberts/vagrant,MiLk/vagrant,janek-warchol/vagrant,obnoxxx/vagrant,mitchellh/vagrant,mwarren/vagrant,jtopper/vagrant,pwnall/vagrant,johntron/vagrant,philoserf/vagrant,jfchevrette/vagrant,benizi/vagrant,mitchellh/vagrant,jfchevrette/vagrant,gitebra/vagrant,sax/vagrant,sni/vagrant,sni/vagrant,jmanero/vagrant,sax/vagrant,legal90/vagrant,sideci-sample/sideci-sample-vagrant,jhoblitt/vagrant,mkuzmin/vagrant,nickryand/vagrant,darkn3rd/vagrant,genome21/vagrant,petems/vagrant,Avira/vagrant,crashlytics/vagrant,bryson/vagrant,mkuzmin/vagrant,kamigerami/vagrant,bshurts/vagrant,fnewberg/vagrant,PatOShea/vagrant,mkuzmin/vagrant,wangfakang/vagrant,cgvarela/vagrant,stephancom/vagrant,carlosefr/vagrant,mwrock/vagrant,darkn3rd/vagrant,jberends/vagrant,channui/vagrant,modulexcite/vagrant,loren-osborn/vagrant,rivy/vagrant,aaam/vagrant,bshurts/vagrant,Endika/vagrant,johntron/vagrant,teotihuacanada/vagrant,jean/vagrant,chrisroberts/vagrant,dustymabe/vagrant,h4ck3rm1k3/vagrant,bheuvel/vagrant,mwrock/vagrant,aneeshusa/vagrant,janek-warchol/vagrant,genome21/vagrant,TheBigBear/vagrant,nickryand/vagrant,tschortsch/vagrant,bdwyertech/vagrant,jkburges/vagrant,bdwyertech/vagrant,blueyed/vagrant,gpkfr/vagrant,evverx/vagrant,ferventcoder/vagrant,tknerr/vagrant,shtouff/vagrant,modulexcite/vagrant,evverx/vagrant,signed8bit/vagrant,PatrickLang/vagrant,aneeshusa/vagrant,zsjohny/vagrant,dharmab/vagrant,benh57/vagrant,taliesins/vagrant,teotihuacanada/vagrant,Chhed13/vagrant,philwrenn/vagrant,cgvarela/vagrant,taliesins/vagrant,tjanez/vagrant,bryson/vagrant,philwrenn/vagrant,crashlytics/vagrant,ArloL/vagrant,genome21/vagrant,pwnall/vagrant,dharmab/vagrant,mpoeter/vagrant,tomfanning/vagrant,signed8bit/vagrant,tbarrongh/vagrant,cgvarela/vagrant,p0deje/vagrant,clinstid/vagrant,otagi/vagrant,sni/vagrant,teotihuacanada/vagrant,vamegh/vagrant,jtopper/vagrant,iNecas/vagrant,philoserf/vagrant,chrisvire/vagrant,patrys/vagrant,stephancom/vagrant,modulexcite/vagrant,zsjohny/vagrant,chrisroberts/vagrant,mwrock/vagrant,carlosefr/vagrant,crashlytics/vagrant,legal90/vagrant,doy/vagrant,taliesins/vagrant,nickryand/vagrant,otagi/vagrant,crashlytics/vagrant,theist/vagrant,jkburges/vagrant,philoserf/vagrant,loren-osborn/vagrant,wangfakang/vagrant,PatrickLang/vagrant,juiceinc/vagrant,philwrenn/vagrant,benizi/vagrant,fnewberg/vagrant,modulexcite/vagrant,zsjohny/vagrant,zsjohny/vagrant,Endika/vagrant,mitchellh/vagrant,bryson/vagrant,lonniev/vagrant,Chhunlong/vagrant,bryson/vagrant,h4ck3rm1k3/vagrant,denisbr/vagrant,TheBigBear/vagrant,ArloL/vagrant,p0deje/vagrant,otagi/vagrant,tbriggs-curse/vagrant,gajdaw/vagrant,BlakeMesdag/vagrant,benizi/vagrant,tbriggs-curse/vagrant,juiceinc/vagrant,doy/vagrant,p0deje/vagrant,juiceinc/vagrant,sax/vagrant,signed8bit/vagrant,petems/vagrant,Chhed13/vagrant,juiceinc/vagrant,h4ck3rm1k3/vagrant,janek-warchol/vagrant,apertoso/vagrant,evverx/vagrant,gajdaw/vagrant,benizi/vagrant,gbarberi/vagrant,chrisvire/vagrant