Adding an API endpoint for a single discussion.
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop
Adding boolean field Post.is_synthesis

In the future, this should be Post.synthesis_id, and it should be an FK to a
published Synthesis.
Capturing query variable 'filters' in /posts/
Implementing filters=syntheses in /posts/
Using idea.longTitle in synthesis email template
Merge branch 'develop' of https://github.com/ImaginationForPeople/assembl into develop