Reverting source.models to 572ad66c

This restores the post.content relationship. Post is no longer a subclass of
Content, and Email is no longer a subclass of Post.
Interim commit for Andre
Add missing file
Putting the discussion.id in a input hidden
adapting the api url to the new pattern
Merge branch 'source-models' into develop

Conflicts:
	assembl/source/models.py
Support multiple discussion, finish moving API to cornice
Merge branch 'cornice' into develop

Conflicts:
	assembl/static/js/app.js
	assembl/static/js/models/idea.js
	assembl/static/js/models/segment.js
	assembl/static/js/views/messageList.js
	assembl/views/api/tests.py
	assembl/views/backbone/views.py
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merging profiles
default values in profile view
Making the ckeditor toolbar stood still in the same place
Fixing url in backbone models
Adding title to synthesis
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Renamed lib.alembic to lib.migration because of strage issue and potential circular import
Merge branch 'tests_refactor' into develop
added missing file
Merge branch 'tests_refactor' into develop
Merge branch 'develop' into tests_refactor