UFO:Alien Invasion Code

* Recompressed all textures in base/textures/tex_base with Trimage image compressor and commited those files, where a filesize reduction of at least 5% (up to 81.5%) was achieved

* [TEXTURE_.MAP_RESCALE-tex_base/wall001-0.5-0.5]
* [TEXTURE_.MAP_RESCALE-tex_base/wall002-0.5-0.5]
* [TEXTURE_.MAP_RESCALE-tex_base/wall003-0.5-0.5]
* [TEXTURE_.MAP_RESCALE-tex_base/wall004-0.5-0.5]
* Rescaled all wall001-wall004 textures on all map files and prefabs (TODO:repeat this operation in data_source)
* Replaced wall001-wall004 jpgs with hq, high-res png versions