Better common phys_field.py
Created originally on Bitbucket by paugier (Pierre Augier)
Was already merged in Bitbucket before import, marked as merged by the import user
- debugging fluidsim.base.output.phys_fields.py
- clean up fluidsim.solvers.ns2d.strat.output.phys_fields.py
- sys.stdout.flush() in base/output/phys_fields.py
- sys.stdout.flush() in base/output/print_stdout.py