Implement drag'n'drop for HLMV
* You can now just drag a .mdl onto the app to open it
Fix normals on balloon_classic LODs and camera.mdl LOD 3
Merge some minor changes for models to load correctly on 64bit
Minor cleanups
Fix false positive on LoadLeafs data validity test
Update AppID for CS:GO to use the new one
Ship a fixed tri1x1.mdl
* Fixed normals, fixed extra weird mesh
Do not reset water reflection/refract textures when they are not used
* From start of game, if expensive water is always disabled (or if the map doesn't have water to begin with), do not clear the RTs. (This would happen only once regardless)