In order to write tests for the catalog functions, they
are made non-static and start taking a 'database' parameter,
which is the name of a file with the preprocessed catalog
entries.
This makes it possible to make test-catalog part of the
normal test suite, since it now only operates on files
in /tmp.
Some more tests are added.
This unifies much of the logic behind them:
- All four will now ofllow the rule that the earlier file and earlier
assignment in the .d/ directories wins. Before, sysctl was the only
outlier, where the later setting always won.
- All four now support getopt() and --help on the command line.
- All four can now handle specification of configuration file names on
the command line to apply. The tools will automatically find them, and
apply them. Previously only tmpfiles could do that. This is useful for
%post scripts in RPMs and suchlike.
- This fixes various error path issues in conf_files_list()
