Add failing tests for TLDs and IDNs

I've been researching autolinking/urlizing/linkifying libraries for [this StackOverflow answer](http://stackoverflow.com/a/21925491/1269037), and Autolinker was one of the most promising ones, and the only one that actually made any claims regarding its features. Cool stuff.

Added some failing tests for actual TLDs and IDNs. The encoded-parentheses one might actually pass, but that depends on the interpretation of what should be shown as the anchor text.