Support for partials

[vra5107]

I just compiled a bunch of files. It seems like there is no support for partials. I get an error when the files are loaded.

[gabrielgrant]

This seems like it should function as a work-around for now: http://stackoverflow.com/a/12148609

We should really add the same -p flag that Handlebars proper got a few months ago: handlebars-lang/handlebars.js#374