* 3.15:
- Multiple misc perl warnings squashed
- Allow a 'runcode' option to buttons for at least Gtk2; use sparingly
- Make the back-button gray if there is no state to go back to
* 3.14:
HTML Generator:
- defaults to using minimal included css
- the "nocss" option can turn this off
- file downloads supported, though it currently creates the file
at screen creation time and thus can't be affected by parameter
changes on the current screen, unlike other backends...
- Misc other bug fixes