Added comment to nsIMIMEService call. If I can ever reproduce the error submit it to FF bugzilla.
Call stopPropagation and preventDefault on the event object as soon as
we determine that we want to quick save. This should prevent some
instances where the context menu gets constructed on quick save
because Cmis.io.save is too slow.
Merged Saveas with the Item object.

A new field was added to Item to determine if the 'Save Image As'
dialog will be opened before saving.
Modified quicksave behavior when saving an item with the 'Save As' option enabled.

If as 'Save As' item is clicked we store the directory that the user
selected. Now if the user calls quicksave on this item it will save to
this stored directory instead of loading the path selection dialog.
Keep track of selected path when creating menu items.

The same way the Firefox download dialog stores the last selected
directory. Path selection when creating menu items will load the
previously selectet root directory when creating menu items.
Hide 'SaveAs' option for sub-menu and setting items.