Add basic Persona support

This allows users to sign in to Hydra using Mozilla Persona accounts.
When a user first sign in, a row in the Users table for the given
Persona identity (an email address) is created automatically.

To do: figure out how to deal with legacy accounts.
Set the character set
Don't redirect to /login if authentication is required

We can just serve the login page in place.
Use the alert class for flash messages
Show sign in as success
Prevent Persona users from setting a password
Show a user's roles in the preferences page
Some escaping
Fix legacy login
Fix audience URL
Link to both the Persona and legacy sign in
Merge branch 'master' into persona

Conflicts:
	src/lib/Hydra/Helper/CatalystUtils.pm
	src/root/layout.tt
	src/root/topbar.tt
	src/root/user.tt
Don't show a password reset button for Persona accounts
Store the account type ("hydra" or "persona") explicitly in the database
Re-enable adding new users via the web interface

Also unify user creation and user editing.
Make sign in a modal dialog box rather than a separate page
Clean up user editing
Slight cleanup in the Persona sign in code
Add a "My jobs" tab to the dashboard

It shows all current jobs of which the user is a maintainer.
Be paranoid about the Persona email address