configure.ac: Shorten deps list, to shorten the link command lengths
NEWS: Spell
RELEASEGUIDE: Clarify instructions
parallel_stereo: Minor tuneup
stereo_pprc: Make symlinks to relative paths
Sessions and Common: Remove code dup, fix for skip-image-normalization

minor
INSTALLGUIDE: We install coreutils automatically on Mac

tmp2
Tools: geodiff now only operates on the union between inputs.
Settings: Made options code easier to read
Code cleanup