Update of composer item's GUI
Add syncGroup to CollapsibleGroupBoxes
replaced "opacity" by "transparency" in the composer GUI
Fix some compiler warnings
Update composer ui files

- Add section headers (should be moved to app stylesheet, and custom label or container class made)
- Enable map grid group box (was disabled)
- Reformat all form layouts to look like rest of app (more grid layout-like, with labels left-aligned and growing entry fields)
- Re-layout map extents group box
- Expand more group boxes by default (increases discovery)