GitLab

- added some new submenus to the file menu for saving project files
- strucutred the file menu
- changed some shortcut keys as they collided with OpenSceneGraph's keys (like "S" for osg statistics)

also if no walnut.cfg is present the program won't hang any longer

This helps to avoid duplicate fiber displays when loading project files with
fiber display in them

[CHANGE] - crashed modules can be deleted now

[ADD] - added multiple options menu for Save Project button
[ADD] - added foundation for ROI saving/reading

activated in preferences file

[CHANGE] - adopted existing project loading to new structure

- additionally corrected the max value of the coronal slice which was wront
- removed unused maxCoronal,maxSaghital and maxAxial properties

currently

 * Viewing parameters are stored as properties.
 * Adjusted structure of the scene graph.
 * Viewing changes are done by numerous callbacks which load the needed data from the EEG classes.
 * Replaced WGE2DManipulator by a new WEEGViewHandler which translates the controls into changes of the new properties.
Now it is possible to see the whole file, but it is just loaded when needed.
In addition to that, some other changes ensued:
 * Electrode labels are always at the left independent from the panning in time.
 * The controls were changed and extended (MMB: panning, RMB: zooming in time, Wheel: scaling of voltage, Wheel+RMB: change spacing of graphs)
 * Resize-window-events are forwarded to a osgViewer::View to be used by a GUIEventHandler attached to this View.
 * Now the EEG view module is automatically added after loading a WEEG2 dataset instead of a WEEG dataset.
 * When adding a new custom dock widget, it is floating with a windows size of 1024x768.

Note that the marked event positions are currently not synchronized with the display, this still has to be adapted.

crashes with the early selected ROIs.