Support SGM files, disable texture options, new modelcompiler tool

[fluffyfreak]

Support SGM files:

@Luomu added the option to export a file from the ModelViewer called SGM which bundles all of the preprocessed model/material/etc data into a single file for quicker loading. However he never enabled loading of it by default in the engine

New modelcompiler tool:

This can convert individual models or it has two batch modes for processing ALL of the models in the ./data/models/ sub-folders.

"usage: modelcompiler [mode] [options...]\n"
"available modes:\n"
" -compile [-c] model compiler\n"
" -batch [-b] batch mode output into users home/Pioneer directory\n"
" -batch inplace [-b inplace] batch mode output into the source folder\n"
" -version [-v] show version\n"
" -help [-h,-?] this help\n"

Running it with -b inplace outputs the .sgm version of the file into the same folder as the .model originated from. This might not be what you desired as .sgm files are loaded in preference to .model files and will NOT automatically pick up any changes you make to your models, textures or other files.

Disable texture options:

This is in response to the issues #2829 & #2435. All textures checked into GitHub are now DDS so I have added warnings to check that the GPU/driver supports them and error out if not.
This comes along with the SGM support since it bundles the textures and materials into it thus making extracting them that little bit trickier.

Andy

[fluffyfreak]

@robn or anyone with more Linux Automake experience than me, I need to some help with getting the modelcompiler built as a separate program.

[fluffyfreak]

Ah ha! Nevermind I worked it out! :)
Been too long since I've done anything with Linux makefiles... no, wait... damn