stereo_corr: No need for interest points if DEM D_sub is used
InterestPointMatching: Print stats first, check matrix later
stereo_corr: Consolidate code
Sessions and InterestPointMatching: Consistent notation
stereo_corr: Local disparity
stereo_corr: Cleanup
IsisIO: Become compliant with ISIS 3.4.3

The dropped the 'get' prefix on some of their methods. They switched
over to QString in more places.
pprc: Have sub images rendered in parallel with sub_tile_size

Sub_tile_size and sub_theads are still important to make sure that
rendering the low res images doesn't allocate a ton of
GB. Cache_tile_aware_render stop us from notice we had a
problem. However if the sub_scale ration is greater than five ... or
if there just existed a really weird homography, it was possible that
stereo_pprc would try to allocate many GB of ram. This brings down the
system because it is swapping memory so hard.
build_vw_asp: added build script
build_vw_asp: fix git commands and number of processors
build_vw_asp: specify gcc4.7