gpgsm: New option --compatibility-flags.
* sm/gpgsm.c (oCompatibilityFlags): New option. (compatibility_flags): new. (main): Parse and print them in verbose mode. * sm/gpgsm.h (opt): Add field compat_glags.: (COMPAT_ALLOW_KA_TO_ENCR): New. * sm/keylist.c (print_capabilities): Take care of the new flag. * sm/certlist.c (cert_usage_p): Ditto.