GRasterSurface underway

Implementation for GRasterSurface has begun properly. I have written implementations for most functions on Windows by this point, although there are obstacles in the way of testing my implementations that I have not solved yet. There are some compile errors that I have not identified the source of yet, and I am not able to run the unit test solution because of permissions issues. Despite this, though, I am making progress toward GRasterSurface working on at least Windows, and once that's done it shouldn't take a terribly long time to have it working on Linux as well. Mac still doesn't have a working proof of concept because nobody has useful information about problems with programming in Cocoa.