Add Chromatic.pm and chromatic/color.c to release/2.8.

These are used in some graph theory problems.
Merge pull request #63 from mgage/release/2.8_fixLinearProgramming

Release/2.8 fix linear programming
Merge pull request #65 from mgage/release/2.8_fixChromatic

Add Chromatic.pm and chromatic/color.c to release/2.8.
Fix conflicts in Chromatic.pm
Merge branch 'release/2.8_OctoberDevelopUpdate' of https://github.com/mgage/pg into release/2.8_OctoberDevelopUpdate