Reveal icon for password field

All password fields now have a "reveal" icon, that can be clicked
to show the password in the filed (if it was actually rendered by
the template) and hide it again.

Change-Id: I1a50b57b0cf9db52b26fd119f53b70febcbdaaea
Implements: blueprint reveal-icon-for-password-field
Merge "Reveal icon for password field"