export CCArmature::disconnectMovementEventSignal() to lua;
modify dragonbones sample to realize CCArmature:connectMovementEventSignal().
Now when CCArmature is playing, we can get the status of moveId: 1 == start, 2 == complete, 3 == loop complete.
Merge pull request #178 from zrong/develop

Modify dragonbones sample to realize CCArmature:connectMovementEventSignal