add SphericalSpherical and UniversalSpherical joints

supersedes #91

Author: baggepinnen

src/Multibody.jl

@@ -154,8 +154,8 @@ include("interfaces.jl")
 export World, world, Mounting1D, Fixed, FixedTranslation, FixedRotation, Body, BodyShape, BodyCylinder, BodyBox, Rope
 include("components.jl")
 
-export Revolute, Prismatic, Planar, Spherical, Universal, GearConstraint, RollingWheelJoint,
-       RollingWheel, FreeMotion, RevolutePlanarLoopConstraint
+export Revolute, Prismatic, Planar, Spherical, Universal, SphericalSpherical, UniversalSpherical,
+GearConstraint, RollingWheelJoint, RollingWheel, FreeMotion, RevolutePlanarLoopConstraint
 include("joints.jl")
 
 export Spring, Damper, SpringDamperParallel, Torque, Force, WorldForce, WorldTorque