[pcf] Replace charmap implementation. PCF comes with charmap lookup table, aka PCF encodings. Using it directly makes FT_Get_Char_Index and FT_Get_Next_Char 4-5 times faster than the original BDF-like binary searches. * src/pcf/pcf.h (PCF_EncodingRec): Removed. (PCF_FaceRec): Remove `nencodings' and `encodings'. * src/pcf/pcfdrivr.c (pcf_cmap_char_{index,next}): Replaced. * src/pcf/pcfread.c (pcf_get_encodings): Store data differently.