Added Latte template engine

Hi there!

This pull-request adding Latte template engine.

Thanks.
I don't think you wanna confuse people with filters and macros. There is no common meaning for "filter", nobody's gonna go and search for templating engine with "filters support", they're going to search for secure templating engine.

I still think that this formulation is better

> Secure, fast and customizable templating engine with context-aware escaping.