Fix bugs of pending keys of animated menu. - When more than one pending key, the animation would be stoped. - Now, we have a cyclic queue to keep at most 15 pending keys to make sure pending keys being dispatched without stop current animation program.

<project>
	<scene src='list.mbsvg' />
	<source src='main.c'/>
	<source src='%n.c'/>
	<source src='%n.h'/>
	<source src='Makefile'/>
</project>