add unless_eq helper

Author: yyx990803

lib/generate.js

@@ -14,6 +14,12 @@ Handlebars.registerHelper('if_eq', function (a, b, opts) {
     : opts.inverse(this)
 })
 
+Handlebars.registerHelper('unless_eq', function (a, b, opts) {
+  return a === b
+    ? opts.inverse(this)
+    : opts.fn(this)
+})
+
 /**
  * Generate a template given a `src` and `dest`.
  *