New:
---

Allow new case bc_uv_t = 'dirichlet_0' for channel flow.

For unknown variables (CASE DEFAULT) call new subroutine user_data_output_dvrp

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, data_output_dvrp, header, init_3d_model, init_grid, init_particles, init_pegrid, modules, package_parin, read_var_list, user_interface, write_var_list


Changed:
-------

Redefine initial nzb_local as the actual total size of topography (later the 
extent of topography in nzb_local is reduced by 1dx at the E topography walls 
and by 1dy at the N topography walls to form the basis for nzb_s_inner); 
for consistency redefine 'single_building' case.

Vertical profiles now based on nzb_s_inner; they are divided by
ngp_2dh_s_inner (scalars, procucts of scalars) and ngp_2dh (staggered velocity
components and their products, procucts of scalars and velocity components),
respectively.

Allow two instead of one digit to specify isosurface and slicer variables.

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

prognostic_equations include the respective wall_*flux in the parameter list of 
calls of diffusion_s. Same as before, only the values of wall_heatflux(0:4) 
can be assigned. At present, wall_humidityflux, wall_qflux, wall_salinityflux, 
and wall_scalarflux are kept zero. diffusion_s uses the respective wall_*flux 
instead of wall_heatflux. This update serves two purposes:
- it avoids errors in calculations with humidity/scalar/salinity and prescribed 
non-zero wall_heatflux,
- it prepares PALM for a possible assignment of wall fluxes of 
humidity/scalar/salinity in a future release.

buoyancy, check_open, data_output_dvrp, diffusion_s, diffusivities, flow_statistics, header, init_3d_model, init_dvrp, init_grid, modules, prognostic_equations


Errors:
------

Bugfix: summation of sums_l_l in diffusivities.

Several bugfixes in the ocean part: Initial density rho is calculated
(init_ocean). Error in initializing u_init and v_init removed
(check_parameters). Calculation of density flux now starts from
nzb+1 (production_e).

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: wavenumber calculation for even nx in routines maketri (poisfft)

Bugfix: assignment of fluxes at walls

Bugfix: absolute value of f must be used when calculating the Blackadar mixing length (init_1d_model)

advec_particles, check_parameters, combine_plot_fields, diffusion_s, diffusivities, init_ocean, init_1d_model, poisfft, production_e