CBD-924:  start to change cgi params to platform and branch

Change-Id: I6d720ccd7534ea19ccf90e3bb562ded9e44c9c0e
CBD-924:  now call with EITHER 'builder' and 'branch' params, OR 'platform', 'bits', 'branch'

For example:

  http://10.3.2.199/cgi-bin/build/scripts/cgi/show_latest_build.cgi/?builder=cs-win2008-x64-20-builder-202&branch=2.0.2

  http://10.3.2.199/cgi-bin/build/scripts/cgi/show_latest_build.cgi/?platform=windows&bits=64&branch=2.0.2

Change-Id: I9d3b636bb4095f30669bc5282d0628c5044ded1f
Merge branch 'master' of http://github.com/couchbase/build