fix errors/warnings in tests

sphinxext tests reference paths that don't exist. this patch
corrects it.

Change-Id: I6a9355a53e2f72de7eab17fc117334843ff8d369
Fix broken sphinx tests.

Change-Id: I2c2046b4ef31c78731f25f3b8e579b05ca0953fb
Add support for manually specifying supported content types in @wsmeexpose.

Closes-bug: #1271317
Change-Id: Ia28a912f4444a6ff77b1feaf2ea6440b0c738e86