[JBIDE-17226] corrected cropping in application wizard

The details view in the application wizard was using a wrapping text
control to show the quickstart summary. To have this working correctly
you have to restrain the horizontal size via GridData widthHint and use
StyledText. StyledText shows/hides the vertical scrollbars
automatically. With Text one needs to measure available & required sizes
(container/Text) and show/hide them upon results & resizing.