Fix for #1622: Validate that facility name is unique on the sharing network (as best we can)
Allow syncing of facilities with the same name.
Fix for #1622: don't allow multiple groups with the same name.
General cleanup of code and comments to follow Django standards a bit more carefully.
Fix for #1839: Clean up facility_user views logic to avoid weird errors on failed POST.
Fix for #1838: only validate passwords when it's a new user (no password), or either of the password fields is non-empty.
Fix for #1885: warn if first/last name combo exists already; allow user to override.
Change for #1885: switch from facility-uniqueness check to zone
For security purposes, only show details on existing usernames to admins.
Validation where fields are inter-dependent are not guaranteed order, and should be done in clean.
Add tests
Get facility set from zone
Reconfiguring to allow field errors to be set directly, updating test accordingly.
Fixing bug (missing self), use more descriptive name
Merge pull request #1962 from bcipolli/1622

Fix for #1882: Validate that facility name is unique on the sharing network (as best we can)