This allows the setting of the error and access file logs, as well as
the access log format. This was done in a similar fashion as one can
configure these ones in the keystone wsgi manifest.
Change-Id: I7e39baa2fefdc63d6f300cb037241846e0871eeb
Depends-On: I5e7d3588b7b3b106813d6d37b55aa812273d04d6