no Nintendo 3DS => null => getPathRoot(null) => exception
provide a fake root if the folder does not exist (to ensure that the
buttons are created with an unavailable path).
Closes#1140
Closes#1137
allows loading of tab separated value text file "savpaths.txt" which can
also be used to 'favorite' locations (ie, the program checks for
duplicate paths and only adds the first).
folder availability checked on form creation
shortcut: press ctrl-F on main window
Thanks @sora10pls !
