[mq]: fix
Use "searchTerms" as the search method in approopriate places.
Rename some variables that are jQuery results.
Improve comments.
Fix the algebra1 demo.
Make matchAsSchema into a method.
Add Expr.isAlphaMatch.
Remove dead code.
Add property "done" to memoized functions.
Make rules.instMultiVars a true no-op if the substitutions do nothing.
Optimize it where some of the substitutions do nothing.
Edit fact statements and code to ensure that entire facts derive
from fact statements.
New utilities: Toy.format, Toy.NestedTimer.
Reorganize and optimize construction of "fresh" type expressions.
Remove unused "copy" method from type expressions.
Move type inference code next to type expression code.
Fix bug in display of ordinals as step numbers.

--HG--
extra : amend_source : 6be7eba7d8637d304f3af15d3eb85e5bab8a41a5
Avoid clearing the step editor input form when the proof selection changes.
Avoid deselecting step or expression when clicking in the step editor input form.
Report cost statistics in the step editor.
Slightly optimize rules.mergeConjunctions; hack on normalizing assumptions.