don't rebind stdlib's os.chdir function

Change-Id: I07d5e8c58007cf716eecb922afb67abe3b53b981
Deprecates V2 controllers

The revocation_list controller method's code was copied from the v2
controller to the v3 controller.  This allows us to cleanly deprecate
the v2 API without impacting the v3 API.

Closes-Bug:#1222696
Change-Id: I0ca7a091a50007c07dfe6942b2653c617ca98e70
Merge "Deprecates V2 controllers"
Merge "don't rebind stdlib's os.chdir function"