QUndo framework - avoid doing things twice

The redo() method is actually called when creating the command, so it is
unecessary (and dangerous) to also "do" the command in the constructor.

This was causing a bug in the outpformats (added twice).
OutputFormat QUndo Framework

- deletion [OK]
- Update: unable to detect modification [KO]
- Create: unable to correctly add to the map object [KO]

To be continued
Ouputformat - Fixing adding an OF

It now works when the default output format exists. I think we have to
create the default output formats at new mapfile initialization.

* tested with wolrd_mapfile [ok]
* with completely blank-new mf [ko]

Because a blank new mapfile does not have even 1 outputformat defined,
it cannot have a one by default, bypassing the OUTPUTFORMAT block
generation when saving the mapfile.
OutputFormat - Modifying seems OK now
Merge remote-tracking branch 'upstream/master'