Add RubyMine debugger gems in their own group

[#56352162]
Support Play 2.0

Play 2.0 dist applications have classpaths similar to Play 2.1.3
stages applications, so use symbolic linking. This minimises the
editing required to the start script.

[#56352162]
Merge 56352162-play-2.0 to master

[Completes #56352162]