Fix parsing of CFF format 1 encoding
Parsing of CFF files would shift the encoding by one when the CFF file used
encoding format 1. The first code point would incorrectly point to .notdef, then
subsequent encodings would be shifted by 1.

Fix is to correctly skip the .notdef glyph when parsing encoding. CFF format
implies that glyph_id 0 is .notdef, so all encodings start with glyph_id 1.
Format 0 handled this correctly, but format 1 was starting with 0 instead of 1.