Lots of general refactoring

Two major changes here:

1) Craftbukkit already includes a sneaky little JSON library hiding out behinds the scenes, so there's no need to include another one - this reduces dependencies for people using your library.

2) I've abstracted all your NMS/OBC class references through some reflection so that this library won't need to have its imports updated every time CraftBukkit updates.

All compiles, all builds, and all functions as expected using your own test methods (which I tweaked a little so I could make sure the sending method was working properly).