Minor tweaks in places
NEWS: Minor rewording
disparitydebug: Minor output display tweak
point2dem: Print out max valid triang error
stereo: Tweaks in parsing options for multiview

stereo: Minor tweak to display the usage all the time

stereo: Minor tweak to display the usage all the time

More tweaks for parsing options
InterestPointMatching: Fix a crash, intersection with datum mail fail
stereo: Print warnings, etc, just once per process
IP matching: Only ISIS camera is single-threaded
ipmatching: A bit more robustness
stereo: maintainability
parallel_stereo: Fix bug for multiview
bundle_adjust: Use multiple-threads for non-ISIS sessions
NEWS: Minor reword
stereo_utils: Minor tweak
dg_mosaic: Accept multispectral data
dg_mosaic: Ensure that multiple bands, if present, are consistent
bundle_adjust: Save cnet as csv function added
bundle_adjust: Refactoring
Common.cc: Ensure that opt.num_threads and vw_settings.num_threads are in sync
Common.h: Make num_threads signed int, for robustness