Release 0.9.9

• Fix JWE payload encryption with AES-GCM
• Add x5u_flag value R_FLAG_IGNORE_REMOTE to avoid downloading remote keys if not required
• Add functions r_jwt_set_full_claims_json_str, r_jwt_get_type, r_jwa_alg_to_str, r_jwa_enc_to_str
• Add API documentation
• Add support for key management algorithms A128GCMKW and A256GCMKW
• Add functions r_jwt_decrypt_nested, r_jwt_verify_signature_nested, r_jwt_parsen, r_jwe_parsen and r_jws_parsen
• Add function r_jwt_validate_claims to validate claims
• Add functions r_jw[se]_add_keys_json_str, r_jw[se]_add_keys_json_t, r_jw[se]_add_keys_pem_der, r_jw[se]_add_keys_gnutls, r_jw[se]_add_key_symmetric
• Add functions r_jwt_add_[sign|enc]_keys_json_str, r_jwt_add_[sign|enc]_keys_json_t, r_jwt_add_[sign|enc]_keys_pem_der, r_jwt_add_[sign|enc]_keys_gnutls, r_jwt_add_[sign|enc]_key_symmetric