Fix definition of `boon-command-map' (#142)

`set-keymap-parent' returns the parent keymap, `boon-moves-map' in this case.

Before this fix, keys not bound in `boon-command-map' and `boon-moves-map'
ended up calling `self-insert-command'. I.e. `suppress-keymap' had no effect.

Author: dkellner

boon-core.el

@@ -27,7 +27,8 @@
 
 (defvar boon-command-map (let ((map (make-sparse-keymap)))
                            (suppress-keymap map 't)
-                           (set-keymap-parent map boon-moves-map))
+                           (set-keymap-parent map boon-moves-map)
+                           map)
   "Keymap used in Boon command mode.
 \\{boon-command-map}")