Log Message:
Changes 2.12.8:
* libgnutls: PKCS-11 back-end was replaced by p11-kit
* libgnutls: gcrypt: replaced occurences of gcry_sexp_nth_mpi (..., 0)
  with gcry_sexp_nth_mpi (..., GCRYMPI_FMT_USG) to fix errors with 1.5.0.
* libgnutls: Verify that a certificate liste specified using
  gnutls_certificate_set_x509_key*(), is sorted according to TLS specification
* libgnutls: Added GNUTLS_X509_CRT_LIST_FAIL_IF_UNSORTED flag for
  gnutls_x509_crt_list_import. It checks whether the list to be imported is
  properly sorted.
* libgnutls: writev_emu: stop on the first incomplete write.
* libgnutls: Fix zlib handling in gnutls.pc.
* certtool: bug fixes in certificate request generation.
* API and ABI modifications: GNUTLS_X509_CRT_LIST_FAIL_IF_UNSORTED:
  New element in gnutls_certificate_import_flags