add a CREDITS file
use square brackets to show the workspace number below the icon
[install] do not set bad version if tag is missing
add a LICENSE file, add copyright info to main source file
avoid flickering thumbnails when re-selecting same window
more fine-grained minimize/restore choices in menu for multiple selections
don't enter persistent mode upon showing quick help
add tooltips to a couple of settings, shorten a couple of descriptions
[install] add uninstall target, make sure to remove symlink without erasing pointed-to directory