Recurse exception handling to better handle '{{}}' in place of recently installed fix (#9548)

* Introduced preliminary idea for infinite recurse exception

* Better handling of infinite recursion

But it could be better still...

* the TransclusionError is a proper error

Moved the magic number to be on the error's class. Not sure if that's
a great idea.

* Fixed minor minor issue that came up in conflict

The minor fix to the jasmine regexp that escaped a '+' somehow
broke some random test.

* Removing patch fix for recursion errors

* Fixed issue where buttton and other widgets don't clean up

* Added release notes for #9548

* Update test-widget.js

If I don't fix those indentations, the entire TW codebase will explode or soemthing.

* Update test-widget.js

These lint problems are wasting my time.

* Fixed all core widgets to not leak when renderChildren fails

* Updated release notes to reflect what I'm actually fixing

* Update test-widget.js

Added warning not to use for-of loop for defining tests. The iterating variable needs to have its own method scope, or it risks being the same value for all tests.

core/modules/widgets/scrollable.js

@@ -168,8 +168,8 @@ ScrollableWidget.prototype.render = function(parent,nextSibling) {
 	this.outerDomNode.className = this["class"] || "";
 	// Insert element
 	parent.insertBefore(this.outerDomNode,nextSibling);
-	this.renderChildren(this.innerDomNode,null);
 	this.domNodes.push(this.outerDomNode);
+	this.renderChildren(this.innerDomNode,null);
 	// If the scroll position is bound to a tiddler
 	if(this.scrollableBind) {
 		// After a delay for rendering, scroll to the bound position