Restore the long-standing (forever) behavior of ulist/uifc.list where

Backspace (the "Delete" key on a MacBookPro keyboard) is treated the same
as ESC (exit).
Make the help status bar more clear in Mac OS X builds that the '+' key
may be used in place of the INSert key to add itesm and that fn-DELete key
sequence is used to delete items (or the '-' key, though that isn't stated).