This is a big commit. I only got to put about 1 hour into this tonight.

Changes:
1.) gdal_module returns true in the case of a success... the return codes seem to always return 1 regardless of what is passed in... so I conformed it to the other tests
2.) ui_module now executes the unit tests before running the plugin. This is not a good idea for normal operation, but for testing purposes, it doens't break the flow of the normal program
3.) test_gdal now includes unit tests for hill shading
4.) test_gdal now includes unit tests for color reliefs (all of them are in there!)

IMPORTANT: YOU SHOULD COMMENT OUT THE TESTS IN THE UI MODULE BEFORE IT GOES TO PROD