#435 - query to fetch pipeline instances that got trigerred off of a material revision
#435 - query to fetch modification with material-instance and revision string
#435 - refactor VSM code to add 'current material' concept
#435 - create VSM given a material-fingerprint and revision
#435 - UI for VSM for material
incorporating feedback to PR. using existing findModificationWithRevision() instead of newly created getModificationFor().
Merged changes from master
Merge pull request #442 from srinivasupadhya/vsm_for_commit

Vsm for commit - Hooking up the links in UI is still pending, but the rest of the commit looks good.