Changes for Old Naming Scheme

If you stick to the old naming scheme some changes are needed:

• The preprocessor define __LEGACY_API must be set (this allows to use the old terminology and old vector/matrix math).
• For read access UVWHandle needs to be replaced by ConstUVWHandle and NormalHandle by ConstNormalHandle.
• On Windows any system specific windows.h include has to be changed to include windows_include.h instead. The header makes sure there is no collision of LONG/ULONG.