Add support for escaping template values

[asdcdow]

I really like the syntax for the Bliss templates. The only thing keeping me from using it is that it doesn't HTML escape template values. This makes it very difficult to to prevent XSS issues. Please add support for doing this by default.

Also, if you do add support for this, make sure you provide a way to bypass the escaping because sometimes you do need to put raw values in templates.

Thanks