Merge pull request #224 from caktus/feature/207-django-upgrade

Upgrade Django
fixes scrolling issue and close #226 ,as the CSS issues are CTE
Merge branch 'develop' into staging
Work on #179, expose Tutorial Handouts to registrants and speakers on front end presentation detail page
Add tutorial registrants field to allow for further enhancements in the system
allow staff to see tutorial handout on presentation detail page
manual merge
working version of Tutorial instructor/student -> class messaging
remove debugger, fix template syntax error
updating strings for translation, tweaking presentation of messages
proof of concept for attendee <--> speaker emailing, tweaks to messaging
update message templates
convert message notification to BCC to protect emails
remove debugger
adding direct email templates for tutorial attendee <--> instructor coms
update direct email template
update docstring
Adding factory for PyConTutorialProposal
Adding basic form tests for pycon.tutorials
add init