Merge pull request #136 from bbandix/perTestBackend

Make EnginioClient and EnginioModel tests use their own backend
Remove old examples
Fix a code snippet
Merge pull request #134 from nierob/smallFixups

fixups
Merge pull request #137 from enginio/dev

Merge dev to master as a preparation for the alpha release
Move the test user preparation function out of the backend manager.
Add helper function to prepare an object type on a backend to be used by tests.
Make the c++ file test use its own backend
Make the QML tests use their own backend.
The tests do not require the ENGINIO_BACKEND_ID and ENGINIO_BACKEND_SECRET
environment variables any more since they manage their own separate backends.