Fixes a bug where flash wasn't enabled for child web views

    Fixes #506

    Adds a listener to the ChildWebViewCreated event so that flash can
    be enabled when necessary. This includes automated tests checking
    that flash is enabled in both the main webview and child webview.

Reviewed By: Bryan Higgins <bhiggins@rim.com>
Tested By: Tracy Li <tli@rim.com>