Make cache-busting optional

Closes #70

lib/proto/parse-options.js

@@ -19,6 +19,7 @@ module.exports = function(options){
     }
   }
   this.options.scrollTo = (typeof this.options.scrollTo === 'undefined') ? 0 : this.options.scrollTo;
+  this.options.cacheBust = (typeof this.options.cacheBust === 'undefined') ? true : this.options.cacheBust
   this.options.debug = this.options.debug || false
 
   // we can’t replace body.outerHTML or head.outerHTML

lib/request.js

@@ -12,7 +12,12 @@ module.exports = function(location, callback) {
     }
   }
 
-  request.open("GET", location + (!/[?&]/.test(location) ? "?" : "&") + (new Date().getTime()), true)
+  // Add a timestamp as part of the query string if cache busting is enabled
+  if (this.options.cacheBust) {
+    location += (!/[?&]/.test(location) ? "?" : "&") + new Date().getTime()
+  }
+
+  request.open("GET", location, true)
   request.setRequestHeader("X-Requested-With", "XMLHttpRequest")
   request.send(null)
   return request