h] = conT(deriv, policy, m, s, delta)
%
%
% *Input arguments:*
%
%   deriv    desired derivative. options:
%        (i)    'dMdm' - derivative of the mean of the predicted control
%                wrt the mean of the input distribution
%        (ii)   'dMds' - derivative of the mean of the predicted control 
%                wrt the variance of the input distribution
%        (iii)  'dMdp' - derivative of the mean of the predicted control 
%                wrt the controller parameters
%        (iv)   'dSdm