deprecated funtions without direct successor

[Andreas Metzler]

Hello,

I have test-built most of the gnutls-depending packages, checking for
build errors with 2.12. 

Afaict there are a couple of recently deprecated functions without
successor. Is this correct, do you have any pointer, suggestions?

gnutls_certificate_get_x509_cas (neon27, openldap)
gnutls_sign_callback_set (neon27)
gnutls_transport_set_lowat (curl, filezilla, gnustep-base,
libgwenhywfar, net6, openvas-libraries, samba4,
xfce4-mailwatch-plugin)

thanks, cu andreas