- in AbstractAnnotationHover, modify
  AnnotationInformationControl.createAnnotationInformation() to
  add scroll bars to the StyledText area that shows the annotation
  text so as to make space when the hover is focused and prevent
  wrapping text in the focused hover
- also in computeSizeHint() use the minimum of preferred width +
  trimsize + 4 and the constrained width so that an unnecessary
  resize does not occur due to trim added on the screen edge

Change-Id: I267fa34378b16515852e2c167e08848172598824
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>