[EuroPython] Talk registration improvement and extending talk submission

[Jacob Hallen]

I have improved the talk registration procedure somewhat more resilient to 
problems:

1. I have increased the timeout from 15 minutes to 1 hour. It turned out that 
Twisted has a hard-coded timeout that triggers in something between 15 and 30 
minutes from the last activity in the session.

2. If you hit the timeout, you will get an error message saying that you 
probably did so. It looks ugly, but it is better than no message at all. 
Making it beautiful would be more of an effort than I have time for right 
now.

We are still a little short on talks; we have a total of 60 hours of talk 
slots, not counting the lightning talk sessions on Wednesday afternoon and 
right now we have talks filling 37 of those hours.

For this reason, I propose that we extend talk submission until 7 May under 
the pretext of having had problems with the talk registration procedure. In 
the mean time,all the track chairs need to canvas their contacts, so that we 
get a nicely filled schedule.

Jacob