Make the UserInputPanel contents scrollable

• Patch Submitted:

  Yes

Sometimes it is required to have lots of controls on one UserInputPanel (e.g. in our product we have a long summary list of configuration variables displayed at the end of the installation process). Unfortunately UserInputPanel does not display all of these controls.
My proposed improvement is to change the implementation of the UserInputPanel so that it contains a vertical scroll. To be exact I propose adding a JPanel that will hold all user input controls and will have the TwoColumnLayout. This JPanel will be put inside a JScrollPane which will be added as a direct and only child of the UserInputPanel.

I've attached a patch of my changes.