CLI: dclab-compress should not write data from basins

[paulmueller]

When using the dclab command line interface (compress, condense, join, repack, split), basin features should not be written to the output file. Instead, only features that are actually in the input file should be present in the output file.

However, there should be a command-line option for including basin features (and optionally which features) in the output file.

This is not to be confused with, but a requisite for #239 which deals with the inclusion of basin definitions in the output file.