Improved parallel communication in PointValue
(closes #4407, closes #3431)
Merge pull request #4453 from aeslaughter/csv-broken

Improved parallel communication in PointValue
Add element containing start point in elementsIntersectedByLine() closes #4458
Merge pull request #4459 from bwspenc/raytracing

Add element containing start point in elementsIntersectedByLine()
Add VectorPostprocessors to get materials along a line closes #4462

This provides an abstract base class, LineMaterialSamplerBase, that
has the basic machinery for extracting the material properties for the
elements along a line, and two derived classes,
LineMaterialRealSampler and LineMaterialSymmTensorSampler, for
extracting data for specific material types.