More functions implemented.  NiNode and NiObjectNET are now good examples of how to deal with pointers.
With implementation of NiNode::GetChildren function, I was able to re-enable the building up of the bind position.

Made all include paths relative so you don't have to set any directories to compile.  Hopefully Amorilia will fix this in the code generation script.
Implemented a few more functions.

Incorporated defines into the h and cpp files I'd already made for NiNode, NiObjectNET, and NiAVObject.

Noticed that I had forgot to include NiObject.cpp in my last commit... unfortunately I've already started splitting off classes into their own files so that's included in this commit as well.
I also noticed that I never implemented the member functions of Ref!  I still haven't, but I was just surprised it's been compiling without complaint.