Add back the --[no-]color flag as deprecated.
Add back the --[no-]color flag as deprecated.

Add back the `--[no-]color` flag as deprecated.

The intellij plugin has been using the wrong flag name for a very long time, and while `color->colors` is now fixed in master for the plugin, this will help to smooth out the transition to the correct flagname.

Testing Done:
tried each of: `--no-color`, `--color`, `--no-colors`, `--colors`

https://travis-ci.org/pantsbuild/pants/builds/92123000

Bugs closed: 2593

Reviewed at https://rbcommons.com/s/twitter/r/3150/

ericzundel/pants,twitter/pants,gmalmquist/pants,UnrememberMe/pants,fkorotkov/pants,benjyw/pants,ericzundel/pants,pombredanne/pants,mateor/pants,jtrobec/pants,cevaris/pants,landism/pants,landism/pants,baroquebobcat/pants,tdyas/pants,pantsbuild/pants,UnrememberMe/pants,dturner-tw/pants,twitter/pants,lahosken/pants,twitter/pants,gmalmquist/pants,foursquare/pants,tdyas/pants,dbentley/pants,peiyuwang/pants,wisechengyi/pants,mateor/pants,kwlzn/pants,baroquebobcat/pants,ericzundel/pants,lahosken/pants,kwlzn/pants,pombredanne/pants,dbentley/pants,peiyuwang/pants,ity/pants,twitter/pants,fkorotkov/pants,twitter/pants,15Dkatz/pants,kwlzn/pants,mateor/pants,cevaris/pants,landism/pants,fkorotkov/pants,pantsbuild/pants,wisechengyi/pants,ity/pants,jtrobec/pants,kwlzn/pants,mateor/pants,pantsbuild/pants,foursquare/pants,tdyas/pants,jtrobec/pants,dturner-tw/pants,landism/pants,UnrememberMe/pants,UnrememberMe/pants,twitter/pants,wisechengyi/pants,cevaris/pants,twitter/pants,gmalmquist/pants,jsirois/pants,jtrobec/pants,peiyuwang/pants,pantsbuild/pants,twitter/pants,ericzundel/pants,baroquebobcat/pants,dbentley/pants,baroquebobcat/pants,wisechengyi/pants,foursquare/pants,pantsbuild/pants,jsirois/pants,benjyw/pants,dbentley/pants,ity/pants,pombredanne/pants,lahosken/pants,lahosken/pants,jsirois/pants,UnrememberMe/pants,ericzundel/pants,foursquare/pants,landism/pants,dturner-tw/pants,foursquare/pants,benjyw/pants,benjyw/pants,mateor/pants,ity/pants,wisechengyi/pants,UnrememberMe/pants,peiyuwang/pants,tdyas/pants,dturner-tw/pants,ity/pants,pombredanne/pants,wisechengyi/pants,foursquare/pants,ericzundel/pants,ericzundel/pants,lahosken/pants,benjyw/pants,benjyw/pants,peiyuwang/pants,ity/pants,dbentley/pants,kwlzn/pants,manasapte/pants,manasapte/pants,baroquebobcat/pants,gmalmquist/pants,wisechengyi/pants,manasapte/pants,gmalmquist/pants,gmalmquist/pants,manasapte/pants,15Dkatz/pants,peiyuwang/pants,landism/pants,pantsbuild/pants,lahosken/pants,twitter/pants,mateor/pants,cevaris/pants,fkorotkov/pants,baroquebobcat/pants,foursquare/pants,manasapte/pants,baroquebobcat/pants,tdyas/pants,15Dkatz/pants,kwlzn/pants,fkorotkov/pants,tdyas/pants,pombredanne/pants,UnrememberMe/pants,15Dkatz/pants,landism/pants,wisechengyi/pants,UnrememberMe/pants,mateor/pants,cevaris/pants,ity/pants,peiyuwang/pants,fkorotkov/pants,foursquare/pants,manasapte/pants,jtrobec/pants,pombredanne/pants,15Dkatz/pants,ericzundel/pants,cevaris/pants,cevaris/pants,fkorotkov/pants,tdyas/pants,mateor/pants,tdyas/pants,baroquebobcat/pants,lahosken/pants,jtrobec/pants,dbentley/pants,gmalmquist/pants,pombredanne/pants,manasapte/pants,jtrobec/pants,lahosken/pants,benjyw/pants,dturner-tw/pants,kwlzn/pants,tdyas/pants,15Dkatz/pants,dturner-tw/pants,15Dkatz/pants,peiyuwang/pants,UnrememberMe/pants,pantsbuild/pants,landism/pants,15Dkatz/pants,dbentley/pants,fkorotkov/pants,wisechengyi/pants,baroquebobcat/pants,dturner-tw/pants,foursquare/pants