Encode headers and params

BaseClient currently fails when non-ascii characters are passed in
paramas and headers. This patch ensures those params are correctly
encoded before the request is made.

The patch adds strutils from oslo and updates gettextutils.

Fixes bug: #1182824

(cherry-picked: db33d99af2b16ae81f815c63a6aea851318a2b34)

Conflicts:
	openstack-common.conf

Change-Id: I12fc2d93b10c43091c1e921be2db1258beb18439
Merge "Encode headers and params" into stable/grizzly