Fix issue with matching partial TLD names in the middle of a word.

Example: 'sencha.etc' was getting linked as: '<a href="http://sencha.et">sencha.et</a>c'

Also fix a few other tests which had a little variation in wording.
Add support for properly handling parenthesis, including ignoring a trailing close parenthesis if there is no matching open parenthesis in the url string.