Fixed some Spawn Icons in the giveweapons module

... Again.

Didn't I already do this? Falco, silkicons are now built into GMOD. The
evidence is in my old SRCDS folder.

And vgui/achievements/ep1_beat_game_onebullet is no longer in GMOD for
clients. We cant FastDL it as thats copyright issues as previously
discussed, so we need to use a different image. The ammobox works fine
for now, until someone feels like finding something better.
Merge pull request #1046 from Redfiend/refactor

Fixed some Spawn Icons in the giveweapons module