Made a couple commits to CVS:
1) Switched "$Shockwave_model:" to "$Shockwave model:" to go with the rest of the variables in ships.tbl and weapons.tbl
2) Finished support to use up to 8 different shockwave animations (including the default, so 7 additional ones) for ships and weapons. Use "$Shockwave Name:" , followed by the animation filename, to specify an anim for a specific ship or weapon. Untested, aside from me making sure that default shockwaves (3D and 2D) still work fine.