Split up Ticket model to support ticket types carrying different
information. Right now, there are three kinds:

* Support Ticket: No additional infomration.
* Venue Ticket: Additionally requires first and last name, T-Shirt size
and optional organization.
* SIM Card Ticket: In addition to Venue Ticket also the address of the
(local German) host is required to be able to activate an ordered SIM
card.
Added basic Django Admin support for extended ticketing.
Reorganized split of ticket models.
Merge remote-tracking branch 'origin/develop' into feature/extended-tickets
Merged changes form development and fixed them.
Merge branch 'feature/extended-tickets' of https://github.com/EuroPython/djep.git into feature/extended-tickets

Conflicts:
	pyconde/attendees/admin.py
	pyconde/attendees/models.py
Add accept_job_offers field

This adds a field to the user profile, we can check to determine whether
the user wants to receive job offers by sponsors, see #78.
Fix #78 - Add ability to send job offers
Fix wording in translations
Further translation fixes
s/adminbox/sponsorshipbox
s/pagetitle/page_title
Don't redirect to success in JobOffer view
Add job offer template
Translate "Reply-To"
Add comment on mail connection
Always send people the the https version
Remain in JobView on success
Merge sponsorship job offer migrations
Add missing import