content

Adding missing set*Color() calls to fix reported bug.

Cause: 
AbstractAnnotationHover extends AbstractInformationControl and does
some setColoring for it's private child composite without updating the
color of the parent structure.

Test:
- Change information hover colors in preference
- Hover over snippet described in bug description

Before: Strip at the bottom was of different color.
After: Strip at the bottom is the same color as inner content.
   (see attached screenshot in bug).

Reviewer note:
- I investigated private setColorAndFont(..). It is only used 
  for coloring of child elements, and only in deferredCreateContent().
  As such, there is no situation where setColorAndFont(..) would be
  called without set*Color() being called first.
  This ensures consistent colors for this class.

Note, after doing a root-cause analysis, I found the same sort-of
issue in a few other classes that extend AbstractInformationControl,
namely:
- BrowserInformationControl
- ExpressionInformationControl
- LinkListInformationControl
I will address those in separate bug because they
1) need the new INFORMATION_ api (instead of further using HOVER_)
2) some are in separate repositories. (jdt/platform)



Change-Id: I837eceaf00b8ab8162f8490a1b48425bfc38210d
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=516420
Signed-off-by: Leo Ufimtsev <lufimtse@redhat.com>