Empty email for users gets saved as an empty string

The actual behavior is that horizon sends an empty string
on the "email" field when creating a new user if the field
isn't filled by the user.
To match the keystone client behaviour, instead of sending
an empty string, this patch sends a "None" value when the
field isn't filled by the user.
By doing this, when creating a new user from both,
keystone client and horizon, a "null" value is stored
under the same conditions.
in the database. This will keep the data consistency.
From the presentation point of view, when a "null" value
is received, it is presented as an empty string instead
of showing "None" on the "email" field of the users table.

Change-Id: Ib5df774b3fe9d82c084f380c9c11aea46b2984aa
Closes-Bug: #1265805
The order of fields have changed for update default quota form.

Changed the ordering of the the fields for update default quota form
so that it now matches the default quota table page.

Change-Id: I76c5b75f30d9db39c83b395bffbf11340b2e0bde
Closes-Bug: #1275892
Replace horizon.utils with an angular one

    Horizon utilitaries are now fully integrated into the angular
application. The object horizon.utils is still available in the
application in order to keep the compatibility, it is a link to the
angular constant object.

Change-Id: I3d44c5c281a8e61e93f4d1b7c3b8b61c128e36ea
Implements: blueprint horizon-angular
Rename UpdateDefaultQuotas to UpdateDefaultQuotasStep

A class with the name of UpdateDefaultQuotas was declared twice in the
same file. Rename one occurrence to UpdateDefaultQuotasStep.

Change-Id: Ie2adb0d540656c5b106607bfc992f553ad1fa45b
Closes-Bug: #1285135
Clean up Cinder client traces in the test output

The Volumes index page has 2 tabs now, for volumes and snapshots. The
calls to list the snapshots were not mocked in a couple of places.

Change-Id: I0f4a59c19b7f5dfb12df41f8c9d3261eea802874
Closes-Bug: #1284665
Merge "Clean up Cinder client traces in the test output"
Merge "Rename UpdateDefaultQuotas to UpdateDefaultQuotasStep"
Merge "The order of fields have changed for update default quota form."
Merge "Empty email for users gets saved as an empty string"
Merge "Replace horizon.utils with an angular one"