js: separate gpgme answer by type of data

• src/Connection.js; src/permittedOperations.js: To avoid further encoding problems, data sent by gpgme is now sorted as either 'payload' or 'info'. Payload data may come in any encoding, and here the 'expected' and 'format' options are used, 'info' data may contain text created by gnupg which may need re-encoding, but this should not be affected by 'expected' and 'format'