#97 C4 redesign

[Rylius]

C4 stays a weapon as it is right now.
+attack drops it to the ground, /zoom in throws it.
/c4 ready readies the fuse in the left hand
While the fuse is ready, +activate detonates all C4 packets. Switching weapons or /c4 unready puts the fuse away again.

Explosions destroy dropped C4 packets instantly.
C4 damage is scaled by HP (max 50), bullets subtract their normal damage.