Fix broken of running animation - Running animation is stop automatically after a certain time. - It is 300ms according MBScene._updateUI(). - It is caused by notification of changing DOM tree. The notification handlers would call MBScene.updateUI() to update framelines and buttons. - MBScene.updateUI() would call MBScene.show() after 300ms, MBScene.show() calls MBScene.parseScene() in turn. - MBScene.parseScene() would remove duplicate group that is using by code of running animation, MBScene.doRunNext(). It make running animation stop. - fixed by setting MBScene.lockui when a running animation is started or stoped.

#ifndef __MB_BACKEND_UTILS_H_
#define __MB_BACKEND_UTILS_H_

#include "mb_backend.h"
#include "mb_timer.h"

/*! \brief A facotry of timer manager implemented with mb_tman_t.
 */
extern mb_timer_factory_t tman_timer_factory;
extern mb_tman_t *tman_timer_man_get_tman(mb_timer_man_t *tm_man);

#endif /* __MB_BACKEND_UTILS_H_ */