Updated docs/configuration.md.
Updated docs/configuration.md.

- Copied the output of --help messages from configure, master, and
  slave.
- The option tables are now in html format.
- Removed the explanation of the default configure flags.

Review: https://reviews.apache.org/r/27556

dforsyth/mesos,jpeach/mesos,verizonlabs/mesos,verizonlabs/mesos,dforsyth/mesos,zmalik/mesos,andschwa/mesos,kaysoky/mesos,reneploetz/mesos,neilconway/mesos,zmalik/mesos,craimbert/mesos,verizonlabs/mesos,asamerh4/mesos,abudnik/mesos,jpeach/mesos,kaysoky/mesos,andschwa/mesos,asamerh4/mesos,zmalik/mesos,jpeach/mesos,zmalik/mesos,neilconway/mesos,dforsyth/mesos,Gilbert88/mesos,andschwa/mesos,gsantovena/mesos,Gilbert88/mesos,dforsyth/mesos,abudnik/mesos,reneploetz/mesos,reneploetz/mesos,yuquanshan/customizedMesos,verizonlabs/mesos,neilconway/mesos,gsantovena/mesos,yuquanshan/customizedMesos,abudnik/mesos,jpeach/mesos,chhsia0/mesos,neilconway/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,craimbert/mesos,chhsia0/mesos,jpeach/mesos,reneploetz/mesos,gsantovena/mesos,Gilbert88/mesos,chhsia0/mesos,craimbert/mesos,yuquanshan/customizedMesos,andschwa/mesos,gsantovena/mesos,Aman-Jain-14/customizedMesos,chhsia0/mesos,verizonlabs/mesos,neilconway/mesos,craimbert/mesos,abudnik/mesos,yuquanshan/customizedMesos,neilconway/mesos,abudnik/mesos,andschwa/mesos,zmalik/mesos,zmalik/mesos,kaysoky/mesos,Gilbert88/mesos,chhsia0/mesos,andschwa/mesos,chhsia0/mesos,asamerh4/mesos,reneploetz/mesos,jpeach/mesos,Aman-Jain-14/customizedMesos,abudnik/mesos,asamerh4/mesos,craimbert/mesos,andschwa/mesos,reneploetz/mesos,dforsyth/mesos,chhsia0/mesos,craimbert/mesos,dforsyth/mesos,kaysoky/mesos,gsantovena/mesos,neilconway/mesos,kaysoky/mesos,reneploetz/mesos,abudnik/mesos,gsantovena/mesos,yuquanshan/customizedMesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,Gilbert88/mesos,verizonlabs/mesos,Aman-Jain-14/customizedMesos,gsantovena/mesos,craimbert/mesos,Gilbert88/mesos,Aman-Jain-14/customizedMesos,dforsyth/mesos,yuquanshan/customizedMesos,zmalik/mesos,kaysoky/mesos,Gilbert88/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,jpeach/mesos,kaysoky/mesos