Fixed unarmed experience scaling with only bash damage

[Xanderga]

Summary

SUMMARY: Bugfixes "Fix unarmed experience gain calculation"

Purpose of change

Unarmed experience was previously calculated with purely bash damage. However, the vast majority of unarmed weapons do not deal purely bash damage, which is the value used for practice for experience calculations. Only two weapons exist that are purely unarmed bash, Cestus and Pair of Steel Knuckles. Unarmed also trained cutting and piercing, but not bashing.

Describe the solution

Change Unarmed so that all damage dealt while unarmed (pierce, bash, and cut) contribute solely to unarmed exp.

Testing

Only have the following enabled for experience gain at level 0:
Piercing
Cutting
Bashing
After killing a zombie while unarmed, experience for the above skills were 0%.
After killing a zombie while armed with a pair of nail knuckles, the above skills were 0%.
After killing a zombie while armed with a cudgel, bashing experience increased.

Only have unarmed enabled:
After killing a zombie while unarmed, unarmed experience increased.
After killing a zombie while armed with a pair of nail knuckles, unarmed experience increased.
After killing a zombie while armed with a cudgel, no experience gained..