Change any and all internal variables, contants, or class names
to reference "sahara" rather than "savanna". Also remove 'Savanna'
from NA comments marking intentional divergence from the nova client.
Map the 'savanna_url' param to 'sahara_url' in the savannaclient to
make sure the change in saharaclient.api.Client.__init__ does not
break existing code.
Partial-implements: blueprint savanna-renaming-client
Change-Id: Ia537a4d43036b44c05a399de0d04482e6029c6bc
02c5cb4a00