update to b2. changes include:

- fixed light cone (prefight)
- fixed bumpmaps for some textures
- reduced filesize
- improved loading times
- improved VIS (should run a lot better now on most systems)
- (hopefully) fixed the crashing issue
- added missing textures
- nerfed rocket attack to do 100 dmg instead of 1000
- nerfed rocket attack projectile to be dodgeable
- nerfed skeleton (removed 3 of 5 spawns)
- improved clipping in some areas
- many brushes are now func_detail to further improve performance
- fixed some texture stretching