Add support for JavaScript alert, confirm, prompt and onbeforeunload dialogs (issue #507).

- Add CefJSDialogHandler and CefJSDialogCallback interfaces.
- Add default dialog implementations for Windows and Mac OS-X.
- Add "JavaScript Dialogs" example to cefclient.
- Change TestHandler::AddResource to ignore the query component when matching URLs.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@594 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

tests/cefclient/cefclient.cpp

@@ -322,6 +322,10 @@ void RunPopupTest(CefRefPtr<CefBrowser> browser) {
       "window.open('http://www.google.com');", "about:blank", 0);
 }
 
+void RunDialogTest(CefRefPtr<CefBrowser> browser) {
+  browser->GetMainFrame()->LoadURL("http://tests/dialogs");
+}
+
 void RunLocalStorageTest(CefRefPtr<CefBrowser> browser) {
   browser->GetMainFrame()->LoadURL("http://tests/localstorage");
 }