- fix ascent/descent in hhea and os/2 to match noto UI expectations,
zero linegap, clear useTypoMetrics bit, set weight to regular (400).
- add missing entries to name table, update revision
- map U+0000 to null glyph (not .notdef)
In addition, this tweaks the Makefile in some small ways:
- quiet zopflipng output somewhat (listen to your cpu fan to know
that something's happening) :-)
- make flag-symlinks target an order-only dependency (it was triggering
quantize+compress even when images hadn't changed)
- add comment about how to bypass make bug if multithread hangs
The new emoji assets (in sync with Android Lollipop) were slightly
smaller in size. Replacing with a corrected size.
Also update the font version to sync with Android again.