More corrections to the 4DVAR adjustment of open boundaries

[arango]

Additional changes were made to the 4DVAR adjustment of open boundaries, ADJUST_BOUNDARY. We need to separate the adjustment of 2D momentum in 3D applications. The modules tl_obc_adjust.F, rp_obc_adjust.F, and ad_obc_adjust.F now have an additional routine to compute the vertical integral of 3D momentum increments used in the 2D momentum adjustments. These are now computed in tl_obc2d_adjust, rp_obc2d_adjust, and ad_obc2d_adjust, respectively.

Also corrected rp_set_depth_bry. This routine is special and now is equivalent to tl_set_depth_bry. The additional terms that are added during the representer (finite amplitude tangent linear) model transformation are not needed here because of the way that the adjustments to the boundary are computed.

As always, many thanks to Andy Moore for his help in debugging and testing this algorithm.