New package quarter-plane.
* packages/quarter-plane/quarter-plane.el
(quarter-plane-saved-symbols): Remove.
(quarter-plane-saved-values): Give a default value.
Don't make permanent-local.
(quarter-plane-mode): Cleanup before re-enabling.
Set change-major-mode-hook.
(global-quarter-plane-mode): Use quarter-plane-mode rather than the
deleted turn-on-quarter-plane-mode.
Commentary fix for quarter-plane.el.