Merge branch 'release/2.1.5'
Merge branch 'develop' of github.com:akvo/akvo-rsr into hotfix/2.1.5.1
Update Release Notes Closes#250
Closes #250
Merge branch 'hotfix/2.1.5.1'
Merge branch 'hotfix/2.1.5.1' into develop
Merge branch 'develop' into hotfix/2.1.5.2
[#224] Implement updating of existing projects via IATI XML

Fix resources of related models so that tastypie works right when updating

Add IATIProjectResource.obj_update() to delete all related objects for
the related resources when IATI XML is PUT to the API.

The deletion is made so that all data related to the project is created
anew by the PUT. This is the only workable way to "update" the
information given that there is no way we can map the IATI XML data that
represents the related objects to the existing objects in RSR.
Merge branch 'develop' of github.com:akvo/akvo-rsr into develop
[#224] Update api/cordaid_importer.py to support PUT

Better feedback when PUTting
Merge branch 'feature/iati_update' into develop