Recording single changes of objects or their specific properties is
completely superfluous as we have full implemented state tracking in all
objects already. Therefore use SerializingObject::saveState() and
SerializingObject::restoreState() in order to implement the undo/redo
functionality.
This is just an initial commit and needs some further work (especially
regarding stability). However even things like undo/redo of
addition/removal of Tracks and TrackContentObjects do work already.
Most files and most of the core classes and their methods have been
renamed to match new coding style conventions:
391 files changed, 25400 insertions(+), 25598 deletions(-)
Furthermore splitted some files where model and view classes were
declared or implemented together in the same file.
Should be tested thoroughly as I might have missed renaming some virtual
methods or SIGNAL/SLOT parameters.
(cherry picked from commit 8c9a9dd14c)
