osgi: be smarter when installing bundles

* Don't install/start the jruby.jar bundle
* Don't start fragment bundles

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
osgi: fix cache pruning bug

The parent directory was being deleted twice causing errors in the logs.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
osgi: lower logging in KillbillActivator

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
Merge branch 'new-paymentpluginapi' of github.com:killbill/killbill into new-paymentpluginapi