* update fonts and metrics so that accents are positioned correctly
* fix degree symbol, move more accents into the 0x2c0-0x2df range
* fix accents in Unicode screenshots
* update jest snapshots, update AccentsText to include requested characters
* update fonts submodule, add unicode chars to AccentsText test
* update submodules after merging its PR
* Make accents zero width
Make the width of an accented character equal to the width of the character,
by making accents zero width. In particular, fixes#1028 (`\ddot\imath`).
This involved reworking all of the accent offset machinery, in particular
skew and accent-hungarian. A bit cleaner now.
Also added support for the new width character metrics in symbolNode.
* Update AccentsText test
* Fix comment
* Support for \' \` \^ \~ \= \u \. \" \r \H \v text-mode accents
* bug fix
* Possible Safari fix
* Forbid text accents in math mode
* Switch to noncombining characters for most accents. Revert Safari change.
* Add tests
* Found non-combining diaresis accent too
