* Use id() for methods returning a string used to represent
some type of object.
* Use displayName() for strings that are meant to be user
visible.
* Quieten some warnings while touching the files anyway.
* Move Factories to their products in the plugins where that
was not done before.
Reviewed-by: dt
Add a title label to the pages. Use QGroupBoxes throughout.
Extend SavedAction to work with checkable QGroupBoxes. Polish UI files,
use common layout for VCS plugins. Performance: Apply only visited
settings pages. Add search keywords.
Task-number: QTCREATOR-26
