[streaming_global] removed unused variable kmid
[streaming_global] allowed multiple grids per process (WARNING: simulations with AMR_bsize set to 3*16 do not give identical output)
[streaming_global] added problem.par that crashes when run on 3, 6, 7, ...  processes and hangs on 5, 9, 10, ... processes
[fargo] impose additional restriction on AMR_bsize (not very effective, more like providing a warning
[fargo] moved fargo arrays from grid_container to cg_level_T
[streaming_global] removed unnecessary import
[cg_level_connected] introduced function find_level to find pointer to a level of given id
corrected intege kind
Merge remote-tracking branch 'origin/master' into fargo_AMR
Merge branch 'master' of github.com:piernik-dev/piernik into fargo_AMR
[fargo] implement real checks for forbidden refinement steps
[gravity] shortened list of public variables
[gravity] removed unused namelist parameters n_gravh and h_grav
[cg_level_connected] comments and cosmetics
[gravity] Call grav_pot_3d after each refinement change to update gp array. Use cg%is_old to update only new grids
[gravity] default_grav_pot_3d also checks for cg%is_old
[problems] updated user gravity routines to use cg%is_old
[piernik] Bugfix for 3ff38c0. import from gravity module has to be conditional
[fargo] do not call fargo routines when fargo is off
[initpiernik] Warn about possible nonconvergence of initial AMR iterations