Change Document.acls from a list to a dict

The format was [("userid", "view", "edit")], it is now
{"userid": ("view", "edit")}
Use mock._patch_stopall instead of stopping individual patches in tests
Use "view" permission to determine documents to show in workspace

... and only give "publishers" permission to publish in publishing
Change delete API to handle content that is not @draft

Close #111
Merge pull request #143 from Connexions/workspace-permission

Workspace permission