niflib: removed -fpermissive flag from Makefile and fixed 32 bit pointer casts for 64 bit build (reported by guidoj, fixed with hints from Alphax, see issue #2788607)

Finished new MatTexCollection helper class which makes it possible to manipulate material properties and texture objects with the same classes regardless of the intended NIF version.
Realized that only read was implemented for files with version < 3.3.0.13, so implemented write for those old versions as well.

Since there seemed to be no way to make pre-main initialization work for statically linking the library, I went back to using a CPP file that includes all the NiObject files and registers each one with the ObjectRegistry.

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.

- There are no longer any defines, things like inheritance class name, NIF attribute variables, and default constructor code are all visible without looking at another file.
- All non-custom parts of the Object files are now totally identical and in the same order, so it will be easier to compare them.
- NiObjects are now completely self-contained.  To remove them from Niflib, you have only to exclude their CPP file from the build.  To add new ones, you only have to include their new CPP file.
- Making a change to a NiObject implementation file only causes that one file to be re-compiled, which is generally much quicker than before since the large obj_define and obj_impl files do not have to be parsed or compiled.
- There are no longer any "Internal" versions of the Read, Write, asString, FixLinks, or GetRefs functions.  Now there is just one function for each of these with pre and post custom code areas (except for GetRefs which I didn't think needed it.)
- Updates to the hierarchy in the XML should now be almost completely automatic.  All that should be necessary to make an update is to add any new NiObject CPP files to the build.
- Changes to the generated parts of the NiObject files can now be made at any time, and immediately applied to all NiObjects without editing each existing one.

Updated to the latest XML, which adds support for NiBinaryVoxelExtraData, NiBinaryVoxelData, NiPSysCollider, NiBone, NiPSysSphericalCollider, and NiTriShapeSkinController.
Removed erroneous bhkMeshShape object.
Added support in the version parsing functions for versions such as "3.03" which were being parsed as "3.3.0.0" before.  These will now be parsed as "3.0.3.0."
All Bridge Commander demo NIF files other than those that contain voxel 3D textures can now be read.
All DAoC demo NIF files except those of version 2.3 and those that do not appear to store NIF data can now be read.

Added functions to NiImage and NiTextureProperty to allow texture name to be manipulated in <= 3.1 files.
Updated ComplexShape to take the above objects into account when deciding whether to include UV coordinates.

Updated Niflib to the latest XML which adds support for bhkMeshShape, NiMultiTextureProperty, NiRawImageData, and NiSequence.

Objects now have a Create methods and register themselves in the global object map with pre-main initialization, making obj_factories.cpp obsolete.

Re-exposed TYPE constants and marked them NIFLIB_API, making the TypeConst function obsolete.  You now must use NiObject::TYPE instead of NiObject::TypeConst() again.

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.

Moved TypeConst function implementation out of header file. Hopefully should fix GCC visibility issue.
Fixed GetIDString virtual function missmatch that was causing the name not to show up when the function was called from a NiObjectRef.
Added Python-specific operator functions to Ref to prevent the wrapper from crashing on Null Refs.