- Rename BrowserID to Persona
- Replace the login via 'BrowserID' button with standard graphical
Persona button.
- Add Persona logo
- Update css style of all availlable themes: raw, aqua, default, primary
school, fresh, sunset, and ultima.
- Change Persona button background for aqua theme

Change-Id: Icf7932dbf3e1dd32660280ab8e269d4b837b3536
Signed-off-by: Son Nguyen <son.nguyen@catalyst.net.nz>