VectorPostprocessor system works closes #3087
Add NodalValueSampler.  It can sample multiple values simultaneously along a sideset/nodeset refs #3087
split NodalValueSampler into a base class so I can use it with other VectorPPs refs #3087
add SideValueSampler refs #3087
add PointValueSampler refs #3087
split PointValueSampler into a base class and reuse it to add LineValueSampler refs 3087
fix issues found during code review on #3118 refs #3087
rename function to declareVector refs #3087
output vector postprocessors by default with csv refs #3087
use the IndirectSort utility that is built into MOOSE remove the new one refs #3087
Merge pull request #3118 from friedmud/vector_pp_3087

VectorPostprocessor System
Merge commit 'ba18337f42bdbeea471cd9cb7d123864bf213c97'