[EuroPython] Deadline for submissions?

[Paul Everitt]

Stefane pointed out that the announcement didn't mention a deadline for 
submissions.  Ouch, we indeed forgot this!

I propose:

   o Submission deadline the third week of April

   o All tracks finish selections two weeks later

This gives:

   o Around 6 weeks from the announcement to the submission deadline

   o Around 6 weeks between "you've been accepted" and the conference,
   to let people make travel decisions

--Paul