Extend fieldmodules to include an "editType" field

This will allow us to provide the right HTML5 input element for things
like colours and dates

boot/boot.js

@@ -606,7 +606,7 @@ $tw.Tiddler = function(/* [fields,] fields */) {
 			} else {
 				// Parse the field with the associated field module (if any)
 				var fieldModule = $tw.Tiddler.fieldModules[t];
-				if(fieldModule) {
+				if(fieldModule && fieldModule.parse) {
 					this.fields[t] = fieldModule.parse.call(this,src[t]);
 				} else {
 					this.fields[t] = src[t];
@@ -633,6 +633,10 @@ $tw.modules.define("$:/boot/tiddlerfields/created","tiddlerfield",{
 	parse: $tw.utils.parseDate,
 	stringify: $tw.utils.stringifyDate
 });
+$tw.modules.define("$:/boot/tiddlerfields/color","tiddlerfield",{
+	name: "color",
+	editType: "color"
+});
 $tw.modules.define("$:/boot/tiddlerfields/tags","tiddlerfield",{
 	name: "tags",
 	parse: $tw.utils.parseStringArray,