Allow region override for url_for

If region is passed in to url_for use that, otherwise continue
to use the region from the user's session.

Fixes bug #1231171

Change-Id: Ia7d2a4f12a3c0d4d45bb918255184d1736f5bddf
Fix typos: "gruop" and "remove from"

Change-Id: If1afd82ffff3f4058c87b675913d4a0d31c52c09
Closes-Bug: #1234119
Merge "Fix typos: "gruop" and "remove from""
Merge "Allow region override for url_for"