* src/data.c (_gpgme_data_release): Free buffers.
(gpgme_data_seek): Adjust from renamed fields.
(gpgme_data_set_flag): Implement new flags.
(_gpgme_data_inbound_handler): Allow the use of a malloced buffer.
(_gpgme_data_outbound_handler): Ditto.
* src/data.h (BUFFER_SIZE): Move out of the struct definition.
(struct gpgme_data): Remove pending filed and introduce inbound and
outbound fields.
* src/conversion.c (_gpgme_wipememory): New.  Taken from GnuPG.
* src/cJSON.c (wipememory): Use this here too.
* tests/run-decrypt.c (main): Add options "--large-buffers" and
"--sensitive".