adapting makemake to parallel netcdf
these blanks are kept in the FC variable, whihc is annoying on small screens
refactoring: netcdf helper routines go to separate module
refactoring: moving routines related to procesorwise snapshot file to own module
condensing code a bit
moving attribute writing routines to nc_helpers

to avoid circular dependencies, had to move ncid_out to data_io
avoding dependence of nc_routines on nc_snapshots
style up main to our standard
line length
removing useless num_simul, was 1 anyway since a few years
moving clock wrappers to clocks module

slightly uggly, but imho less uggly then heaving them in the main programme
moving define_io_appendix to data_io
tidy up
removing homo stuff
adding an option to write the snapshots directly in the chunking

needed for kerner and instaseis
tidy up
tidy up
tidy up - this module seem to be pretty useless, and connected to that

there is a bunch of functions never called in subpar mapping