Changed TrackWithVertexRefSelector to a stream module.

Static analysis and helgrind showed it is safe to convert this
module to a stream module. Thread performance analysis showed
this conversion is needed for efficient threading.
To do the conversion, I introduced ObjectSelectorStream templated
base class.
Merge pull request #4091 from Dr15Jones/makeTrackWithVertexRefSelectorStreamModule_72

Changed TrackWithVertexRefSelector to a stream module.
Merge remote branch 'origin/CMSSW_7_2_X' into CMSSW_7_0_X