* src/argparse.c (struct variable_s): New.
(struct _gpgrt_argparse_internal_s): New fields expand, if_cond,
if_active and vartbl.
(deinitialize): Free vartbl.
(initialize): Clear new vars.
(get_var): New.
(substitute_vars): New.
(set_variable): New.
(handle_meta_if): New.
(handle_meta_let): New.
(handle_meta_getenv): New.
(handle_meta_echo): Re-implement in terms of variabale substitution.
(handle_meta_expand): New.
(handle_metacmd): Add new meta commands.
(_gpgrt_argparse): Expand values if enabled.
(_gpgrt_argparse): Take care of conditions.
(_gpgrt_argparser): Reset some state at the end of a file.
* tests/etc/t-argparse.conf: Adjust for changed system variables.
* tests/t-argparse.c (my_strusage): Add a value for a version test.
(main): Add new option "street".
* tests/t-argparse.conf: A couple if additions for the new conditions.

trusted-key $tkey