Fixes freezing occuring on linux while running tests

server_connectorTest - alternating port prevents
exceptions not catchable in JS for httpd server when the socket
and the port remains open after httpd.stop() callback

support - changes the window on which `setTimeout()` is ran in dialogs.
If the timeout is ran on the main window the `dialog` object appears to
lose certain properties and not respond to interactions completely.

test/content/support.js

@@ -137,7 +137,7 @@ function waitForDialog(onOpen, button='accept', url) {
 			function acceptWhenEnabled() {
 				// Handle delayed buttons
 				if (dialog.document.documentElement.getButton(button).disabled) {
-					setTimeout(function () {
+					dialog.setTimeout(function () {
 						acceptWhenEnabled();
 					}, 250);
 				}