Modify autolink with regular expression

[alexzhan]

Modify autolink using regular expression from http://daringfireball.net/2010/07/improved_regex_for_matching_urls Code from : https://github.com/facebook/tornado/blob/master/tornado/escape.py

[alexzhan]

@livid This commit also adds some functions not registerd to the django template library. Email with this type : [email protected] will not be figured out anymore.