Improve the final fading state.

- Fade out completely the last time, ie fade to black rather than
  fading down half way then turning off.

- Ensure the first fade had the mode displayed while fading out.

Signed-off-by: Russell Steicke <russells@adelie.cx>
Roll quicker.

Rolling can still be extended by tapping during the roll, but the
default roll time is quite short.

The time that we spend waiting for the second tap, to change mode, is
also much shorter.

Signed-off-by: Russell Steicke <russells@adelie.cx>