moving things from Jeb's branch. Still under way
numerical derivatives of gradient and hessian. Rotation angle can be controlled from the input (using "debugrot" keyword).
reproduced the closed-virtual diagonal hessian
support functions for active indices
gradients fine with kramers on
intermediate checkin - still wrong
minor fixes
attempt to do G(1,2), but totally wrong
Hessian works with kramers pairs.

I forgot to multiply J^-1/2