Freezing Collage instances

[tabularelf]

This'll add in a mode for Collage instances to be frozen, when there's no more images needed to be added to it. This will perform a possible number of things.

-Stores the image data in a more linear fashion (as opposed to passing and accessing struct data for specific UV info/texture pages, as scoping into other structs is slow, but for Collage it's super easy to work with for dynamic texture pages)
-Converts the surface + buffer into a sprite to let GameMaker handle it (no needing to check the surface)
-Disallow saving/loading, packing images, and anything else that involves surfaces + buffers (technically some aspects of this is still possible, but I'm disallowing it mainly due to concerns on conversion to and from surfaces/sprites.)