Added utility for spliting path and filenames
(refs #3544)
Added Function for reading image data
(refs #3544)
Added tests for ImageFunction
(closes #3544)
Fixed voxel calculation; added flipping
(closes #3650)
Merge pull request #3610 from aeslaughter/vtkimage-3544

Created Function for reading and sampling 2D/3D image data
Merge commit 'bd91348200ea542ed2e1c6bb877c9cc7b70cf863'