Embed the template text into the layer file rather than the AST.

Turns out that it's problematic even to create the AST at build time, because then
(during the build) handlebars.js will create dummy custom elements (ex: <d-button>)
for introspection.  They are used to find out when to call element.foo = false
rather than element.foo = "false".

Creating the dummy elements first requires running the code to define the custom elements.
That wasn't working right during builds, because the javascript files were
referencing symbols that don't exist in Node, such as HTMLElement.

Rolls back more of (and most of) 2c0633f.

Fixes #438 for real, and refs #432.

handlebars.js

@@ -9,6 +9,11 @@
  * Both functions are meant
  * to be run in the context of the widget, so that properties are available through `this`.
  *
+ * Could also theoretically be used by a build-tool to precompile templates, assuming you loaded
+ * [jsdom](https://github.com/tmpvar/jsdom) to provide methods like `document.createElement()`.
+ * But the problem is that the build tool has to load the definitions for the custom elements
+ * referenced in the templates, in order to get the types of their properties.
+ *
  * Template has a format like:
  *
  * ```html
@@ -90,7 +95,6 @@ define([
 		 * @private
 		 */
 		parse: function (templateNode, xmlns) {
-			/* jshint maxcomplexity:15 */
 			// Get tag name, reversing the tag renaming done in toDom()
 			var tag = templateNode.hasAttribute("is") ? templateNode.getAttribute("is") :
 					templateNode.tagName.replace(/^template-/i, "").toLowerCase(),
@@ -124,24 +128,14 @@ define([
 				}
 			}
 
-			// Process children.
-			var children = handlebars.parseChildren(templateNode, xmlns);
-
-			// Return AST structure pruning empty arrays etc.  Minimizes size of serialized object.
-			function hasMembers(obj) {
-				/* jshint unused: false */
-				for (var key in obj) {
-					return true;
-				}
-				return false;
-			}
-			var ret = { tag: tag };
-			if (xmlns) { ret.xmlns = xmlns; }
-			if (hasMembers(attributes)) { ret.attributes = attributes; }
-			if (hasMembers(connects)) { ret.connects = connects; }
-			if (children.length) { ret.children = children; }
-			if (hasMembers(attachPoints)) { ret.attachPoints = attachPoints; }
-			return ret;
+			return {
+				tag: tag,
+				xmlns: xmlns,
+				attributes: attributes,
+				connects: connects,
+				children: handlebars.parseChildren(templateNode, xmlns),
+				attachPoints: attachPoints
+			};
 		},
 
 		/**
@@ -218,6 +212,7 @@ define([
 			return children.slice(0, lastRealNode + 1); // slice() removes trailing whitespace nodes
 		},
 
+
 		/**
 		 * Neutralize custom element tags.
 		 * Rename all the elements in the template so that:
@@ -347,26 +342,26 @@ define([
 			onload();
 		};
 
-		// Inline the template AST and list of dependencies into the layer file.
+		// Inline the template text and list of dependencies into the layer file.
 		handlebars.write = function (pluginName, moduleName, write) {
-			var dom = jsdom(handlebars.neutralizeTags(templateText)),
-				template = dom.querySelector("template-template"),
+			var dom = jsdom(templateText),
+				template = dom.querySelector("template"),
 				requiresAttr = template.getAttribute("requires") || template.getAttribute("data-requires");
 			templateRequires = requiresAttr ? requiresAttr.split(/,\s*/) : [];
 			template.removeAttribute("requires");
 			template.removeAttribute("data-requires");
 
-			var moduleRequires = ["delite/Template"].concat(templateRequires);
-			var tree = handlebars.parse(template);
-			var moduleText = "define(" + JSON.stringify(moduleRequires) + ", function(Template){\n" +
-				"\treturn (new Template(" + JSON.stringify(tree) + ")).func;\n" +
+			var moduleRequires = [module.id].concat(templateRequires);
+			var moduleText = "define(" + JSON.stringify(moduleRequires) +  ", function(handlebars){\n" +
+				"\treturn handlebars.compile(" + JSON.stringify(template.outerHTML) + ");\n" +
 				"});";
 			write.asModule(pluginName + "!" + moduleName, moduleText);
 		};
 
 		// Notify builder to take dependencies specified in requires="..." attribute, and inline them into the layer.
 		handlebars.addModules = function (pluginName, resource, addModules) {
 			addModules(templateRequires);
+
 		};
 	}