Switch the bundled mincho font from a Source Han Serif JP subset to a
subset of IPA Mincho, which has monospace ASCII glyphs.
IPA Mincho's hhea ascent/descent already match its OS/2 typo metrics, so
adjust_metrics.py is no longer needed. However, IPA Mincho is distributed
under the IPA Font License v1.0, under which a subset is a "Derived
Program"; Article 3.1(4) forbids the derived font's name from containing
the licensed program's name ("IPA"). Add rename_font.py to rewrite the
name table accordingly, and replace licenses/mincho.txt with the IPA Font
License.
This rewrites the `ascent` and `descent` values in the `hhea` table of
the font, so that the height of the surface returned by `TTF_Render*`
will be the same as the `ptsize` passed to `TTF_OpenFont`. (MTLc3m.ttf
already have this property.)
This fixes the text rendering issue in Tsumamigui2 and Yoru ga Kuru.
kichikuou