core: Add parser for meta commands to gpgrt_argparser.
* src/gpg-error.h.in (ARGPARSE_INVALID_META): New (ARGPARSE_UNKNOWN_META, ARGPARSE_UNEXPECTED_META): New. * src/argparse.c (struct _gpgrt_argparse_internal_s): Add flag insysconfig. (initialize): Init flag. Add error strings. (_gpgrt_argparser): Set that flag. (_gpgrt_argparse): Add parsing of meta commands. * tests/etc/t-argparse.conf: Add some test cases. * tests/t-argparse.conf: Ditto. * tests/t-argparse.c (main): Die only after printing all warnings.
Noe that this is just the framework to add meta commands to the global
config file. We also need to get away from fixes test config files
and create them on the fly to that we are able to test also errors.
- GnuPG-bug-id: T4788