New:
---

Polygon reduction for topography and ground plate isosurface. Reduction level
for buildings can be chosen with parameter cluster_size. (init_dvrp)

External pressure gradient (check_parameters, header, init_3d_model, modules, 
parin, prognostic_equations, read_var_list, write_var_list)

New topography case 'single_street_canyon' (header, init_grid, modules, parin, 
read_var_list, user_check_parameters, user_header, user_init_grid, write_var_list)

Option to predefine a target bulk velocity for conserve_volume_flow 
(check_parameters, header, init_3d_model, modules, parin, read_var_list, 
write_var_list)

check_parameters, init_dvrp, init_grid, init_3d_model, header, modules, package_parin, parin, prognostic_equations, read_var_list, user_check_parameters, user_header, user_init_grid, write_var_list


Changed:
-------

Output of messages replaced by message handling routine.
First constant in array den also defined as type double. (eqn_state_seawater)

advec_particles, eqn_state_seawater, sort_particles


Errors:
------

Bugfix: several tail counters are initialized, particle_tail_coordinates is
only written to file if its third index is > 0, arrays for tails are allocated
with a minimum size of 10 tails if there is no tail initially (init_particles,
advec_particles)

Bugfix: pressure included for profile output (check_parameters)

Bugfix: Type of count and count_rate changed to default INTEGER on NEC machines
(cpu_log)

advec_particles, check_parameters, cpu_log, init_particles