Add new "print tiddler" button for the view toolbar

It works by opening the tiddler in a new window and then triggering the browser print dialogue.

core/modules/startup/windows.js

@@ -29,6 +29,7 @@ exports.startup = function() {
 			title = event.param || event.tiddlerTitle,
 			paramObject = event.paramObject || {},
 			template = paramObject.template || "$:/core/templates/single.tiddler.window",
+			print = paramObject.print === "yes",
 			width = paramObject.width || "700",
 			height = paramObject.height || "600",
 			variables = $tw.utils.extend({},paramObject,{currentTiddler: title});
@@ -62,6 +63,10 @@ exports.startup = function() {
 		var parser = $tw.wiki.parseTiddler(template),
 			widgetNode = $tw.wiki.makeWidget(parser,{document: srcDocument, parentWidget: $tw.rootWidget, variables: variables});
 		widgetNode.render(srcDocument.body,srcDocument.body.firstChild);
+		// Print the window if required
+		if(print) {
+				srcWindow.print();
+		}
 		// Function to handle refreshes
 		refreshHandler = function(changes) {
 			if(styleWidgetNode.refresh(changes,styleContainer,null)) {