datetime webservice arguments errors triggering 500

[mtholder]

http://www.reelab.net/phylografter/study/modified_list.json/url?from=2014-05-24T10:40:56
works, but using isoformat to create the "from" arg:
http://www.reelab.net/phylografter/study/modified_list.json/url?from=2014-05-24T10:40:56.434231

causes a 500. We should probably be more flexible on formats, and return status code 400 + a message.
Not the highest priority, obviously...

[pmidford]

I'll have a look.