Kinematics: Switchable kins should default to identity (joint) mode

[Sigma1912]

Switchable kinematics eg 'genserkins', 'pumakins' currently default to 'world' (or 'genserkins') mode.
If the kinematic model fails (eg in a singularity) the controller switches off and cannot be recovered because there is no way to switch to joint mode and move away from the problematic pose.