moredt calculates useful inertia tensor perturbation quantities
for an elastic moon with constant-time-lag response.
didk,didt,did2t   partials of delta i wrt k2 or k2t or time-deriv of latter
diddk,diddt,didd2t similar partials for delta i dot
didkmx,didtmx,did2tmx partials of above wrt earth mass

calculate perturbations to inertia tensor & time derivs.
also save partials of these wrt earth mass for later use in calculating
partials of the angular acceleration
note that the angular jerk has a component proportional to the earth
mass and so gives a mass dependence of the rotational part of the
second time derivative

calculate sensitivity of delta I and delta I dot to change in the
rotation state, to be used in calculating the partial derivatives
of the angular acceleration, and set up for partials wrt parameters
if iparm.gt.1 then also calculate sensitivity to orbit state

dw = angular acc, as supplied in the main entry
k  = love number
t  = scaled time lag
didy, diddy = 3x3x6 arrays, partials of delta I and delta I dot
wrt rotation state vector
additional information passed through common:
dwdy = partials of w wrt rotation state
ddwdy = partials (to leading order) of dw wrt rotation state
dsxdy = partials of selenodetic earth coords wrt euler angles
drtdy = partials of selenodetic transformation matrix wrt euler angles
dwddx = partials (to leading order) of dw wrt orbit state

dependence of angular jerk on moment-of-inertia ratios
(it would be more efficient to calculate the jerk this way, by
multiplying these components respectively by alpha,beta,gamma --
but the intermediate quantities in the more laborious matrix
and cross product method are saved and reused in other
calculations)

Calculate partials of elasticity/dissipation corrections wrt parameters
Input:
dw = angular acc, as supplied in the main entry, i.e., before correction
k  = love number
t  = scaled time lag
Other information in common:
Ddwdp = partial of rigid-body angular acceleration, not yet corrected
W1,W2,W3= angular velocity
I0,I0i = mean inertia tensor and its inverse
alpha,beta,gamma = moment-of-inertia ratios
Dalpha,Dbeta,Dgamma = partials of moment-of-inertia ratios wrt all parms
Output:
ddidp  = partial of inertia tensor correction
ddiddp = partial of inertia tensor rate correction

The only parameter dependence of the gravitational acceleration is upon
Mass(3), aside from a second-order dependence upon Mass(10), which we
ignore here.  This dependence is purely radial, while the Coriolis
acceleration dependence is purely tangential.