Unify uses of `\coerce`, put universe levels first

All macros that involve universe levels take the levels first, so it
makes sense for `\coerce` to do the same.
Explain the algorithmic judgment `\eqtermpath`
Merge branch 'master' of github.com:andrejbauer/tt

Conflicts:
	doc/brazil.tex
Formatting & cosmetics, `\coerces` order of args.
Better handling of universe indices.