Use single root for nif in WriteNifTree and ResolveMissingLinkStack, to make interface consistent with the rest of niflib.

Moved Object Registration/Creation functionality into new ObjectRegistry class.  Hopefully this fixes the issue with the object map not being initialized yet since it is a static member of the class and should theoretically be initialized before code in functions of that class can be executed.  Seems to work for me, but I'll wait until Tazpn tests it to declare it fixed.

Updated user's guide.

More documentation improvements.  Added documentation to NiDynamicEffect-derived objects, removed some obsolete examples, and replaced remaining references to "block" with "object" wherever possible.

Moved ListAncestors and FindCommonAncestor helper functions from inside of NiGeometry to public interface.

Laying the groundwork for Niflib to be able to work on systems with different endian types.  All Read/Write functions now take NifInfo structures which are based by const reference.  These are also passed into the NifStream functions so they will have access to the requested endian type of the NIF as well.  Also added endian detection and swapping functions.

Replaced _WRITE, _READ, _STRING, AND _FIXLINKS defines with the corresponding internal function call.
Replaced STANDARD_INTERNAL_FUNCTIONS with the internal function signatures.
Made my Doxygen config file use relative paths and added it to SVN so everyone can generate the same documentation for themselves.
Removed includes WZ added to ComplexShape.  These were not missing, they are up to the user to include if they wish.

CheckNifHeader -> GetNifVersion
GetVersion -> ParseVersionString
IsVersionSupported -> IsSupportedVersion
Added new function, FormatVersionString, to format integer version numbers as a #.#.#.# string.
GetNifVersion so it no longer returns VER_UNSUPPORTED.  It now always returns the actual version value, if possible, which can be passed to IsSupportedVersion if desired.
GetNifVersion now supports version numbers lower than 4.
Added versions 4.0.0.0 and 10.1.0.106 to version constants and IsSupportedVersion function.
Updated some documentation.

Changed WriteNifTree, and WriteFileGroup functions to take NifInfo structures instead of version and user_version arguments.
Changed ReadNifList and ReadNifTree to optionally fill a passed in NifInfo structure with information from the header of the NIF file they read.
Fixed some tabs that were done with spaces instead of actual tab characters.
Updated from XML.

1. Update NiStencilProperty based on Shon's changes
2. Rewrote large chunks of WriteFileGroup related routines.
3. Added a WriteNifTree which allows for multiple roots (not exposed publically)
4. Added option to BindSkin to scene instead of skeleton root.
5. Fixed bug in RemoveController
6. Added helpers to NiControllerManager for sequence management
7. Propegated user_version in routines which take a version

1. Add BSBound unknown values.
2. Update MotionSystem enum
3. Add LOD Bone Controller handler
4. Fix website references

Renamed CreateBlock to CreateObject and made it clear that it is not necessary for the user to call this function unless s/he is working through Python.
Removed BlocksInMemory function.  Call NiObject::NumObjectsInMemory instead.
Removed CreateBlock template since new keyword can be used.
Implemented GetScale and SetScale functions of bhkNiTriStripsShape to fix linker errors when compiling Python wrapper.

2. Put back changes that Shon rolled back to so that exporter compiles again
3. Put in new typesafe helper for creating nodes so we dont have to rely on strings.

Created a new ComplexShape class which can currently be used to automatically split the sort of complicated mesh that contains per-point-per-face attributes into NiTriShape classes.  Should support skinning as well, but has not been tested.
Added TexCoord == operator.
Changed type of Triangle members to unsigned short.
Color4 now defaults to all zeros.
NiAVObject::AddProperty now takes a const argument.
Fixed exception in NiTexturingProperty to throw a runtime_error instead of a string.
NiTriBasedGeom::BindSkin should now automatically finds the skeleton root by itself.  The skeleton_root argument has been removed.

Tried to implement MergeNifTrees for KF files with a NiControllerSequence root.  Untested.

Moved version constants to a separate file to clear up problems with no longer including NIF_IO.h in niflib.h.