Add Suite#timeElapsed
Fix whitespace errors
Expose error message formatting function for use by reporters
Add JUnit XML reporter

Fixes #102. Closes #193.

Also-by: Mangala SSS Khalsa <mkhalsa@sitepen.com>
Also-by: Jason Cheatham <j.cheatham@gmail.com>
Merge branch 'master' into geezer

Conflicts:
	lib/Suite.js
	lib/reporters/html.js
	lib/util.js
	tests/unit/all.js