Use portable exit function
Move video preview into main window
Make use of WITH-LISTBOX
Limit window size to keep high-res cameras from overflowing the screen
Raise the window when deiconifying
Return empty-set on close

When the windows is closed, delete all images and return as if none were taken. Prompt for confirmation if pictures have been captured.
Support deleting multi-item selections

Note that this shouldn't be necessary for this app, since only one item should ever be selected.
Add widget-manager function
Use regular screen coords instead of last-message coords.

Fixes an issue where the coordinates would be off by a significant amount when other window events occurred (closing a window, expanding the systray on windows 7).
Add the OPTIONS getter to complement the SETFable setter.
Refresh device list when combobox drops down
Set the video source from the combobox's device list
Add util func
Add classic tk::label widget class

The implementation reuses the ttk::label class, so support is partial.
Factor out picture removal
Use a default "no selected image" notice instead of a black image.
Don't show the previews until a source has been selected
Comments and whitespace
Re-display "no selected image" notice when deleting the last image
Use clearer close condition