use python-dateutil to parse the dates

I'm pretty bad at remembering of what the datetime format is.  This pull request adds in using the most excellent python-dateutil, which parses anything that my resembling a date and parsing it to a datetime object. Of course, if you don't put in a year, it will make it the current year.

This also much destroys putting in  any date formats. This pull request still has them in the configuration but, if you decided to accept it, I would make the changes in removing them. 

Let me know what you think.