Add 3 new internal API calls for audit log

Hi,

This is the jBPM part of a new feature: to have a REST API in bpm-console to query already finished process/node/task instances.

This request build-depends on https://github.com/bpmc/bpm-console/pull/6, and I locally needed the http://people.freedesktop.org/~vmiklos/2012/jbpm-depend-on-bpm-console-master.patch patch to make jbpm master depend on bpm-console master.

Please review, and merge if it looks good.

Thanks,

Miklos