From SF patch #852334.

comments, docstrings or error messages. I fixed two minor things in
test_winreg.py ("didn't" -> "Didn't" and "Didnt" -> "Didn't").

There is a minor style issue involved: Guido seems to have preferred English
grammar (behaviour, honour) in a couple places. This patch changes that to
American, which is the more prominent style in the source. I prefer English
myself, so if English is preferred, I'd be happy to supply a patch myself ;)

and the "key" keyword parameter was used to invoke .go(), use the directory
of the selected file as the stored directory to return to when the same key
is used again.  This is useful since the user may well entry at least part
of the path in the filename box instead of doing a lot of clicking around in
the listboxes.

- When dragging the mouse in either listbox, the *first* entry
clicked on is selected rather than the last (but the last one is
highlighted).

This is done by changing the bindtags so that our binding is executed
after the default binding (which sets the 'active' index to the last
item selected), and using 'active' instead of 'anchor' as the index to
ask for.

- Support ~[user] expansion.

- Remember last directory and pattern; optional 'key' argument
specifies different memory locations.

- Absolutify pathnames if possible.

- WM close event cancels the dialog.

- First arg to go() can be either a directory or a file (renamed to
dir_of_file); defaults to current directory.