quadtree.h: protect some internal variables
quadtree.h: protect some internal variables

Signed-off-by: Steven Noonan <steven@uplinklabs.net>

Signed-off-by: prophile <4665d361aaf271b139147017031ea99df777ca5a@gmail.com>
prophile/crisscross,prophile/crisscross,prophile/crisscross,tycho/crisscross,tycho/crisscross,tycho/crisscross