This function will automatically convert URL's into 'clickable' links. The function does not break the use of the [url] bbcode tags at all. The following types of url's are automatically converted:
- Matches an "xxxx://yyyy" URL at the start of a line, or after a space.
- Matches a "www|ftp.xxxx.yyyy[/zzzz]" kinda lazy URL thing
- Matches an email@domain type address at the start of a line, or after a space.
