Partial support for {% now %} template tag.

The YUI strftime library has been adapted to execute as one of mango's
methods.  Most localization support has been stripped from the module, and
due to Django's funny decision to exclude % characters from strftime
formatting strings, that change has been applied to the code as well.

Unfortunately, neither Django nor Python use the same formatting
keys as the chosen library (it doesn't look as though there is a standard),
so this will need further attention before it's ready to go.

Date_Format shortcuts are also a TODO.

Signed-off-by: David Arbuckle <dintlu@gmail.com>
Attaching the mango.template object to the DOM when rendered in the loop.

This enables examination of the template source code via the template's
source attribute.  I've added a console.log() statement that can be copied
and pasted for quick access.

Signed-off-by: David Arbuckle <dintlu@gmail.com>