Various usability fixes:

- Use default JFace foreground color for viewer elements, instead of always declaring black, to improve readability of elements in Dark theme
- Create checkbox and radio buttons with SWT contructor, instead of toolkit to get theme appropriate colors.
- Reduce common code in StereotypeSectionManager to have a single API for getting the active selection
- Change stereotype button to 'View' instead of 'Edit' for inherited stereotypes
- Correctly pass isEditable=false for custom dialogs when viewing inherited stereotypes
- Don't mark editor dirty after pressing 'OK' button after viewing an inherited stereotype
- Sort stereotypes first by inherited stereotypes, and then by name.

Change-Id: I1711f0f1642541e4078bef29a7162e00fbe146bd
12 files changed