Added an Origin variable to HTG sources, to generalize further

Change-Id: I9fd0081453d1ca57cdef4b7597f05d602e78fd0d
Added a test for a bi-material case

Change-Id: Id6dcfb3b52868ceeb20087d1d7a46913ad2bebe4
White space clean up

Change-Id: I5b0fc413c2bbfb02cd80ef3da108db9b6682364d
Merge topic 'add_bi_material_case_to_HTG_tests' into master

50166da6 White space clean up
4df8f236 Added a test for a bi-material case
897663a4 Added an Origin variable to HTG sources, to generalize further