Use the decimal point only for the final roll.

This also removes the use of the left side decimal point, which some
people interpreted as meaning "2.0" .

Signed-off-by: Russell Steicke <russells@adelie.cx>
Show the current mode earlier after a roll.

Signed-off-by: Russell Steicke <russells@adelie.cx>
Correct some comments and docco.

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