Obsolete octcdf

[Alexander Barth]

Hi all,
For quite a time the functionality of the octcdf package has been
superseded by the netcdf package. I propose to remove the octcdf
package from the official package list and to place it in the
unmaintained section (unless somebody wants to maintain it). Maybe we
can add a note next to the package name such as "replaced by the
netcdf package".

Regards,
Alex