Overall buildable balance adjustments

[dGr8LookinSparky]

• [ ] Don't have simultaneous buildable placement slow down building, instead slow down the build times proportional to the bp lost from regen.
• [ ] Increase the max hp decay of buildables by a lot.
• [ ] Get rid of weapon clips and move all of that to the ammo capacities.
• [ ] Increase buildable hp for everything accordingly.
• [ ] Decrease the effectiveness of trappers
• [ ] Decrease the slimer damage by half.
• [ ] Move the slimer sucking behaviour to bg_pmove.c
• [ ] Decrease damage output of buildables in general.