Rename Mob source files to CamelCase

Rename Cavespider.cpp to CaveSpider.cpp

Rename Cavespider.h to CaveSpider.h

Rename Magmacube.cpp to MagmaCube.cpp

Rename Magmacube.h to MagmaCube.h

Rename Zombiepigman.cpp to ZombiePigman.cpp

Rename Zombiepigman.h to ZombiePigman.h
Merge pull request #1 from archshift/rename-mob-squashed

Rename Mob source files to CamelCase