Implemented with two API additions:
1) For element declaration handler support:
XML_FreeContentModel
2) Exposing Expat's memory allocation functions:
XML_MemMalloc
XML_MemRealloc
XML_MemFree
* Changed macro for static linking from _STATIC to XML_STATIC
and modified expat.h accordingly
* Added ReadMe file to Win32 subdirectory documenting Windows builds
* Changed static build settings to create libraries with names different
from the Dll stub library libexpat(w).lib