* m4/gpg-error.m4: Update.
* m4/ksba.m4: Update.
* m4/libgcrypt.m4: Update.
* configure.ac (NEED_GPG_ERROR_VERSION): Don't require newer.
* src/ntbtls.m4: Don't require AM_PATH_GPG_ERROR.  Use GPGRT_CONFIG
when it is confirmed that it is available and working well.  Fall back
to detecting NTBTLS_CONFIG, if not.