Formatting.

Moving some internal structures and constants from freetype.h to ftobjs.h.

Finally removing FT_LOAD_ANTI_ALIAS.

Cleaning up all error codes.  Only the used ones have survived :-)

Removed unused FT_MAX_GLYPH_FORMATS constant.

T2 error codes are now in the range 0x500-0x5FF (instead of `TrueDoc').

Some minor improvements of error return values.

Finally fixing error code values in ftraster and ftgrays to be compliant
with all other FT error codes.