Implement more django 1.7 migration semantic
Recreate migrations with newer django version
Temporary requirements
Fix support for custom user models
Exclude MySQL/PY3/Django1.7 from test matrix
Fix test matrix
switch back to divio repositories for plugins
Update travis file
Fix travis file
Add documentation on Django 1.7 migrations
Promote Django 1.7 environments except MySQL
Merge pull request #3401 from yakky/django_17_take2

Django 1.7 migrations