gpgconf: New command --show-configs.
* tools/gpgconf.c (aShowConfigs): New. (opts): Add --show-configs. (CUTLINE_FMT): New. (show_version_gnupg): Add arg "prefix" and adjust caller. (my_copy_file): New. (show_configs_one_file): New.New. (show_configs): New. (main): Call show_configs.
The ability to have a consolidated list of all config files is very
useful for support cases. This is in particular important due to the
global config files and their conditional constructs.
- Signed-off-by: Werner Koch <email@example.com>