New:
---

Pressure boundary conditions for vertical walls added to the multigrid solver.
They are applied using new wall flag arrays (wall_flags_..) which are defined
for each grid level. New argument gls added to routine user_init_grid
(user_interface).

Frequence of sorting particles can be controlled with new particles_par
parameter dt_sort_particles. Sorting is moved from the SGS timestep loop in
advec_particles after the end of this loop.

advec_particles, check_parameters, header, init_grid, init_particles, init_pegrid, modules, package_parin, read_var_list, user_interface, write_var_list


Changed:
-------

Status of 3D-volume NetCDF data file only depends on switch netcdf_64bit_3d (check_open)

check_open


Errors:
------

Bugfix: pleft/pright changed to pnorth/psouth in sendrecv of particle tail
numbers along y, small bugfixes in the SGS part (advec_particles)

Bugfix: model_string needed a default value (combine_plot_fields)

Bugfix: initializing u_init and v_init in case of ocean runs (check_parameters)

advec_particles, check_parameters, combine_plot_fields