Added textField getter to StandaloneTextInputDialog.  This allows the user to modify parameters of the text field such as autocapitalization.  Also added support for dismissal of the dialog followed by instantiating it again.  Still no support for the "show" button being pressed while the dialog is already showing.  Might have to support this by just a client side check to see if the dialog currently in scope is already showing.
Added property isShowing to StandaloneTextInputDialog.  When instantiating an instance of the dialog, you should first check to see if the in-scope instance is showing.  If it is already showing, re-instantiating will cause a crash.