Reduce warnings for MS Visual Studio 2010. * src/autofit/afhints.c (af_glyph_hints_get_num_segments, af_glyph_hints_get_segment_offset) [!FT_DEBUG_AUTOFIT]: Provide return value. * src/cff/cffgload.c (cff_slot_load): Add cast. * src/truetype/ttobjs.c (tt_check_trickyness_sfnt_ids): Use proper loop variable type.