* Add code to allow each editing window it's own undo/redo count.
* Add code to allow for infinite undo/redo when count is set to 0.
* Add edit control to all editing windows general options dialog for
user configuration of undo/redo count.
* Add code to save and restore undo/redo count for each editing window.
Now these parameters are stored in user config, not project config ( they are not really related to a given project, they are just a setup during an edition),
and the schematic editor and the component editor have now separate parameters, because they are separate editors with different constraints.
component editor: repeat pin enhancement (from and idea of Edward Johns)
Ensure some values initialized by the schematic editor and used by libedit are also initialized in libedit even if the schematic editor was not started.
Remove useless commands (save/load project config) in libedit, because now they have no sense.
jean-pierre charras
Chris Pavlina