Now that handlebars.js doesn't consider 0 == true by default anymore, add support for includeZero.
Our #if helper is fully compatible with handlebars.js.
I really think this is a bad idea, but let's support implicit context in #each.
(cf https://github.com/wycats/handlebars.js/issues/671)
Adding some tests that were apparently failing in handlebars.js
another test that was apparently failing in handlebars.js