pgp_parse: added event handler hooks to decode_stream
pgp_parse: export key_id/1
implemented Mnesia key storage
eks_submit: store imported keys
extracted function pgp_parse:decode_public_key/1
store 8-byte issuer ID lookup table
pgp_keystore: implemented get_issuer_keys/1
pgp_parse:verify_signature_packet: verify non-self sigs
pgp_parse:decode_signed_subpacket: fixed missing offset