Vega Strike Code

Make mesh_tool perform the same vertex de-duplication than the engine.
This enables off-line optimization and saves some effort from the
runtime, not to mention smaller files.

Do not draw super-tiny meshes (less than 2.5 pixels squared).
This was set at 0.5, but since it's computed based on the bounding disc,
and it usually is bigger than the mesh itself, 0.5 was overly
conservative. 2.5 gives better empirical results.

Trivial simplification: read once instead of four times

vegaserver has to be built with the NO_GFX define

Fix: Savegame corruption when a fleet ship is stationed at a base whose
name contains spaces.

Fixed normals for Rlaan_Commerce_Center and Seaxbane

Fixed normals for Diligence and Koala

Various artwork fixes:
- Fixed inverted normals in several models
- Fixed zeroed normals in a couple models (had to re-import from
masters or set usenormals=0)
- Fixed smoothing groups in Hawking
- Switched normalmaps to DXT5nm (note: CINEMUT-NM is somewhat
compatible with DXT5nm, so existing normalmaps should work almost the
same). For further normal maps, use
nvcompress -bc3nm input.png output.texture
- Integrated normalmaps that were present in masters and not in-game
* usually, they were as bumpmaps, used gimp's normalmap plugin
- Renamed a few .png textures to .texture (standard extension is
.texture)

Support DXT5nm normalmaps, natively supported by nvcompress

Cleaned up Ox: removed around 50k invisible faces, huge speed
improvement for braindead GPUs.