Expansion and improvements to the menu bar of the main window.
This corresponds to one component of the patch_II file attached to https://gna.org/task/?6847 by Michael Bieri (https://gna.org/users/michaelbieri).
Many new entries have been created and menu hot keys have been added for all entries.
Authored by: bugman 2010-01-14
Parent: [r10212]
Child: [r10214]
