Remove obsolete references to YUI in comments.
Fix test: testTermSet.
Support web server MIME types and compression better with standard file naming.
Move jQuery to a new "lib" directory; make "jc.py" compile jsc into a jsc/ dir.
Rename proof.js to proof.jsc.

--HG--
rename : js/jquery-1.9.1.js => lib/jquery-1.9.1.js
rename : proof.js => proof.jsc
Add qunit to the source tree.
Convert tests to use QUnit.
Modify indentation throughout tests, add a comment.
Remove vestiges of YUI, no functional changes.
Update headings, wording, and the example proof on the "Introduction" page.
Make "show assumptions" a basic rule.
Rename tutorial.html to introduction.html and fix links.

--HG--
rename : tutorial.html => introduction.html
Simplify and improve text mathification.
Give proof steps a border that can become visible when hovered or selected.
Distinguish selecting a step at the UI level versus the API level,
where it can mean that some subexpression is selected.
Automatically convert operators in the rule selection menu to Unicode
(with conversion from ASCII math operators to Unicode operators).
Update the introduction page for easier reading and to reflect the current UI.