Fixed compile error when I turned off physics definitions.

Fixed the following compile error.
cocos2d\extensions\physics-nodes\ccphysicssprite.cpp(305): error C4716:
'cocos2d::extension::PhysicsSprite::getRotation' : must return a value
and more..

Conditions:
CC_USE_PHYSICS = 0
CC_ENABLE_CHIPMUNK_INTEGRATION = 0
CC_ENABLE_BOX2D_INTEGRATION = 0