Merge pull request #248 from mikeh/master

MOBSDK-688: App crash when avatar not returned by repository
Fix: Unit test failure fixes
Merge pull request #249 from tmughal/master

Fix: Unit test failure fixes
MOBSDK-692: listingContext is never used in AlfrescoPublicAPIWorkflowService's retrieveTasksWithListingContext:completionBlock:
Merge pull request #250 from tmughal/master

MOBSDK-692
MOBSDK-683: Change the way the repository handles the mandatory aspect part of the model
Merge pull request #251 from gavincornwell/master

MOBSDK-683
Add support for the PublicAPI
Fix unit tests to work against PublicAPI correctly
Fix rendition code to retrieve the given rendition name and not just the first one returned by the server
Tidy & fix logic around PublicAPI version support when creating a session