* src/gpgme.h.in (struct _gpgme_subkey): Add field CURVE.
* src/key.c (gpgme_key_unref): Free CURVE.
* src/keylist.c (keylist_colon_handler): Set CURVE.
* src/gpgme.c (gpgme_release): For failsafe reasons reset engine and
engine info after freeing.
--
The engine hack is useful in case the other release functions
accidently call engine release.