gpgsm: New option --assert-validsig.
* sm/gpgsm.c (oAssertValidsig, oAssertKeyusage): New. (opts): Add options --assert0validsig and --assert-keyusage. (assert_validsig_true): New global var. (main): Set options. (gpgsm_exit): Implement --assert-validsig. * sm/gpgsm.h (opt): Add fields assert_validsig and assert_keyusage. * sm/verify.c (gpgsm_verify): Set assert_validsig_true.
This option will be used by internal use of gpgsm.
Note that --assert-keyusage is not yet implemented.