Remove deprecation warnings relating to api-paste

Remove deprecation warnings relating to api-paste

Remove deprecation warnings and backwards compatibility introduced by
commit c355d68a. This commit was introduce in havana and backported to
grizzly. It relates to config options in api-paste.ini.

This commit removes the following deprecated items:
 * cinder.api.auth:CinderKeystoneContext
 * cinder.api.auth:pipeline_factory
 * cinder.api.openstack:FaultWrapper
 * cinder.api.openstack.urlmap:urlmap_factory
 * cinder.api.openstack.volume:APIRouter
 * cinder.api.openstack.volume.versions.Versions
 * cinder.api.sizelimit:RequestBodySizeLimiter

Change-Id: If7c055be0d257dee570da1db4adce2df6e73db14