simple markdown hyperlinks

[maphew]

Something to consider adding to the default markdown extensions (to allow simpler creation of hyperlinks): https://github.com/daGrevis/mdx_linkify

[posativ]

Two dependencies to detect a URL, not bad. Maybe I'd like to use the skeleton and a custom URL detection based on python's urllib.

By the way, markdown also supports <http://example.com/> (http://example.com/).