-fix in:
bool CAnimatedMeshSceneNode::removeChild(ISceneNode* child)
found by ssexton

-added requested getJointCount() in AnimatedMeshSceneNode, which simply calls getJointCount on the held mesh

-added CSkinnedMesh::isStatic()

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@1051 dfc29bdd-3216-0410-991c-e03cc46cb475