introduce namespace croposp
set include statements in compilation units appropriate

This commit had to be rebased and appears out of chronological order.

confirmed: program passes correct header date to libdatrwxx; file contains
wrong value

problem: sigfit produces unreasonable data start time values upon output of
residuals file

a new option for resaseda provides the shrink option in the resample function
of the interpolator

  - automatically convert comma to whitespace in
    coordinate parameters
  - support creation of info data