[multigrid] skip corner update in residuum calculations where possible
[gravity] skip corner update for the potential from selfgravitation
[multigrid_gravity] removed boundary uptdate that was always overwritten in gravity::source_terms_grav
disable optimization implemented in 896a9f3fdc7dee103793368663e5d65eca1ad665
psize = 1,1,1 removed from various problem.par as it is default for long, long time
norm_tol = 1.e-6 removed from various problem.par files
vars in problem.par are now specified in one line - much easier to expand the list
removed outdated references to level_max parameter in MULTIGRID_SOLVER namelist
removed obsolete parameter nsmoof from /MULTIGRID_GRAVITY/
removed obsolete parameter fft_full_relax from /MULTIGRID_GRAVITY/
Merge pull request #18 from gawrysz/cosmetics

Cosmetics
Merge pull request #15 from gawrysz/skip_corners_multigrid_gravity

Skip corners multigrid gravity