Instead of creating a separate, foreign context menu, and to have the
same menu-items than on tree-view.

That will result in the following additional menu items for
shortcuts-view:
- UCA's on mounted devices
- Menu item "Properties" on available bookmarks and mounted devices
- Menu item "SendTo" on available bookmarks and mounted devices
- Menu item "create folder" on available bookmarks and mounted devices
- Menu item "open with" on available bookmarks and mounted devices
- Menu itema "copy/paste" on available bookmarks and mounted devices
- Show menu-items tooltip text in the statusbar