dirmngr: Add support for hkps keyservers.
* dirmngr/dirmngr.c: Include gnutls.h. (opts): Add --gnutls-debug and --hkp-cacert. (opt_gnutls_debug, my_gnutls_log): New. (set_debug): Set gnutls log level. (parse_rereadable_options): Register a CA file. (main): Init GNUTLS. * dirmngr/ks-engine-hkp.c (ks_hkp_help): Support hkps. (send_request): Ditto.