Math font macros in superscripts now enclosed in braces.  Example:
1^\mathsf{W} becomes 1^{\mathsf{W}}.

This makes no difference to the resulting typeset material, but makes
it possible to use ^ as a *macro* rather than the math superscript
token.  There are some packages that make ^ an active character to
make superscript (and subscript) handling more flexible.  The ePub
conversion class is one of these.
Another math font in a superscript that could do with being in braces.
fix sort order in index
fix some too-long lines in ustrade format
explain ctx judgment more, fix #315
errata
Merge pull request #325 from loopspace/upstream

enclose math font commands in superscripts in braces.
eliminate a superfluous space
Merge branch 'master' of github.com:HoTT/book
Merge pull request #327 from mikeshulman/ctx

explain ctx judgment more, fix #315
Merge pull request #328 from mikeshulman/errata

Make a list of errata
Merge pull request #326 from mikeshulman/formatting

fix some too-long lines in ustrade format
Fix file permissions

The files .gitignore and torus-clipped.xcf were
executable by accident.
Merge pull request #329 from vog/fix-permissions

Fix file permissions