1.6/mt haml

Support for hybrid haml/twig throught the MtHaml library. #59
https://github.com/arnaud-lb/MtHaml
Only works with MtHaml > 1.1.1

Example of use:
```
{% haml %}
!!!
%html
	%head
		%title Register
	%body
		%h1 Register
		= form_open(url("submit"))
		= form_input("email")
		= form_close()