Problem parsing microsoft rocketbox models

[DavidLSmyth]

Rocketbox models have spaces in their joint names (e.g. JOINT Bip01 Neck). When parsing joint names some of this info gets lost. In line 112 of bvh.py this can be fixed with
joints.append(' '.join(joint.value[1:]))

I haven't tested this with other models but can submit a pull request if this would be useful to update.