Improve draging bone
Improve draging bone

kerryChen95/boneAnimationEditor,AlloyTeamDev/AlloyAnimation,AlloyTeam/AlloyAnimation,AlloyTeamDev/AlloyAnimation,AlloyTeam/AlloyAnimation,kerryChen95/AlloyStick,AlloyTeam/AlloyAnimation,kerryChen95/boneAnimationEditor,AlloyTeamDev/AlloyAnimation,kerryChen95/AlloyStick,kerryChen95/boneAnimationEditor