Allow handler to set HTTP headers.
Merge pull request #30 from Gizra/http-headers

Allow handler to set HTTP headers.

For example: $this->updateEntity() will $this->setHttpHeaders('Status', 201);
Properly check access to entity and property using the wrapper.
Merge pull request #29 from Gizra/entity-access

Properly check access to entity and property using the wrapper.
Remove access test that was moved to own class.
Merge master