Add gpgme_set/get_status_cb().
* src/gpgme.h.in (gpgme_set_status_cb): New. (gpgme_get_status_cb): New. (gpgme_status_cb_t): New. * src/gpgme.c (gpgme_set_status_cb): New. (gpgme_get_status_cb): New. * src/context.h (status_cb): New. (status_cb_value): New. * src/gpgme.def: Export new symbols. * src/libgpgme.vers: Ditto. * doc/gpgme.texi: Document these new functions.
This callback function is used to forward status messages from gpg back
to the client.