[rubygems] Jruby 1.7.17-SNAPSHOT

this needs some fixes on the jruby side so it is still WIP

until jruby fixes things we are stuck with jruby-1.7.12
Updating to a snapshot of jruby now is probably not a good idea.  Ive no idea what their release schedule is like, and we are working to wrap up this effort... so putting a SNAPSHOT of a core dependency of this plugin in now is probably not a good plan... unless its absolutely needed to resolve some critical problem... and we have good idea that we can get release on time for use to deliver release.