Improved menu structure of file, edit and window menu. Removed ambiguous shortcuts, improved focus handling for operating the GUI with the keyboard. Added new shortcuts to focus subwindows directly. * files-dockwidget: Set focus proxy to the current directory line edit. * history-dockwidget: Set focus proxy to the inline search bar. * file-editor: Removed and improved shortcuts. * main-window: Added new slots for not only showing/hiding subwindows, but also for focussing them directly with Ctrl+0,1..4. Improved menu structure.

--- a/gui/src/files-dockwidget.cc
+++ b/gui/src/files-dockwidget.cc
@@ -97,6 +97,8 @@
 
   connect (this, SIGNAL (visibilityChanged (bool)),
            this, SLOT (handle_visibility_changed (bool)));
+
+  setFocusProxy (_current_directory);
 }
 
 void