Added legacy support for plugins detecting MCPC. Fixes #1272, #1187

Many plugins are still checking getName() or getVersion() for MCPC so I
have decided to keep the name within both strings until plugins adapt to
new Cauldron name.

* Added support for NMS/OBC package versions R2 and R3. This should allow
latest CraftBukkit plugins to load correctly assuming they do not call a
new method added post 1.7.2.