Multilingual, custom e-mail message to new members

Added a simple templating function for more flexibility.
Add first person to member early, so that a proper e-mail greeting may
be included.
Replace password requirements with quality meter

Password requirements were an annoyance, so remove them and instead use
Dropbox's zxcvbn library to give users an estimate of password quality.
Include Dropbox's brief advice on what makes a good password.
Increase password-field size, and allow passwords with up to 255
characters. (An arbitrary limit, but should be larger than most people
want, and I've tested that MySQL handles them fine.)

The most important TODOs:
Internationalization of JavaScript
Include other form fields when evaluating passwords
Move submodules to a new 'lib' directory
Add password meter to password-change form

Also, remove password validation I overlooked earlier.
Scan JavaScript files for gettext.
Apply RequireJS to password-quality meter

This allows for easier dependency handling. We'll also be adding i18n
dependencies soon.
Better password-quality meter styles

Transitions are friendlier. Solid, thicker border is clearer.
Generate JSON files for translation using php-po2json
JavaScript i18n using Jed

Only applied to password-quality meter so far. It should also be applied
to the Google map.
Use zxcvbn.js instead of -async.js, since RequireJS now handles the
async part.
Make RequireJS load for any page.
Expose Jed as _() instead

This limits us somewhat, but we can always add plural support later,
e.g. by adding delegation to the other Jed methods.
Norwegian Bokmål strings
Load the current language dynamically, and rename to messages.js

If it cannot be loaded, fall back to null translation.
The 'messages.js' name lets us vary only a single, predictable element
of the path to the translation file.
Make password field required

now that it doesn't have further requirements
Norwegian Bokmål strings