crylink projectiles redesigned (it now resembles a flak cannon)

crylink projectiles redesigned (it now resembles a flak cannon)
electro rebalanced to be a bit like the q1 rl/gl
tracer model added to fireBullet (optional per call)
adjusted uzi/shotgun shoot origin and casing origin to be more correct
some other tweaks
added default.cfg for easier maintenance (since it has to be updated so often)
default.cfg g_balance_* cvars are now set instead of seta, so they aren't saved to config (was annoying to maintain)

git-svn-id: svn://svn.icculus.org/nexuiz/trunk@274 f962a42d-fe04-0410-a3ab-8c8b0445ebaa