[type42] Fix auto-hinting.

The autohinter could not access the base (unscaled) outline in the
child TrueType glyph slot. We now share the internal parts between
the parent and child glyph slots. Fixes #1057.

* src/type42/t42objs.c (T42_GlyphSlot_Init): Remove the internal parts
of `T42_GlyphSlot' and replace it with the child TrueType structure.
(T42_GlyphSlot_Done): Updated accordingly.
2 files changed