First (untested) attempt to handle HTML tag names with a = sign in them.
Replace jQuery-based XPath calculation with native one from dom-text-mapper.
Use jQuery-based XPath construction by default, manual as a fall-back.
Added manual XPath evaluation fallback for bogus elements.
Revert "First (untested) attempt to handle HTML tag names with a = sign in them."

This reverts commit 0d1ef70eabf5281bf763f1e6a467666da94c530d, which was unsufficient to solve the problem.
Stronger measures have been introduced since this first weak attempt.
Added some comments
indentation and whitespace fixes
rename $.dummyXPathEvaluate -> $.xpath
split xpath utilities out into a separate file
browsers don't always throw the right exception
Merge branch 'pure_dom_xpath'

Conflicts:
	src/extensions.coffee