Pull request #69: Dev

Merge in TPSH/ckanext-odsh from dev to master

* commit '37b3b00e': (67 commits)
  fixes unit tests
  takes id directly from package object
  uses context=None
  removes basic list from collection_read
  fixes link to thumbnail image
  uses snippet package_list for list of collection members
  removes temporary files
  removes json from logging in OdshApiController
  adds basic list of collection members
  WIP: adds template for collection list
  adds workaround for missing relationships
  adds link to Barrierefreiheitserklaerung
  adds metadatum 'accessibility'
  fixes bugs in odsh_dcat_de_profile
  removes deprecated method get_collection_id
  adds integration test for thumbnail plugin
  adds integration test for thumbnail generation from frontend
  prepares integration testing of thumbnail plugin
  adds reminder for changing interface
  implements feature: use first uploaded pdf for thumbnail generation
  ...