Fix weapon physics

[kyleconroy]

Our weapons have always felt a bit "off". In conjunction with the #1884, let's take a look at how other games do weapon damage and make the appropriate changes.

[didory123]

The Castlevania weapons seem like a good reference. Only one weapon motion, similar to ours (overhead swing)

http://www.youtube.com/watch?v=S2kQ-fC3Apw&feature=player_detailpage#t=47

[CalebJohn]

Was this fixed by #1860 ?

[niamu]

I dislike how our current weapon details rely on so many manually set values. Weapon knockback as well as attack delays should be dependent on damage. I also think special damage should stun an enemy for a short time.

I think our weapon animations are generally too slow as well. @8bitgentleman had an idea to add weight to weapons. That may be useful to calculate the speed of an animation if we add that. But I'm very hesitant to add another manually set value to weapons.

Overall, I think we rely too much on manually set values and need to start calculating attributes based on values that are pre-existing. This will improve the feel of the game greatly.