Help buttons on Chris's sshkeyDist dialogs now open HTML help,
which is nice, but unfortunately, the user can't scroll down
on the HTML help window while the Launcher is displaying a
modal dialog.  The user can Cancel from the modal dialog and
then scroll down to read the rest of the help.  Perhaps instead
of using app-modal dialogs, we should be using locally modal
dialogs, e.g. http://wiki.wxpython.org/ParentModalDialog