cleaned up memory deallocation in read_cert_url()

That caused unexpected results when loading PKCS #11 URLs.
Reported by Joseph Peruski.
doc update
guile: Add bindings for 'gnutls_server_name_set'.

This adds the 'set-session-server-name!' procedure and the
'server-name-type' enum type.
guile: Restore cross-reference in 'set-session-priorities!' docstring.

This had been destroyed in 32d90395.
restrict the number of non-fatal errors gnutls_handshake() can return
protect DTLS clients that don't handle GNUTLS_E_LARGE_PACKET from an infinite loop on handshake
do not allow GNUTLS_E_LARGE_PACKET to be returned from non-DTLS sessions

Conflicts:
	lib/gnutls_handshake.c
doc update
use wait and retransmit when receiving session tickets
doc update
doc update
rnd: if RUSAGE_THREAD fails try RUSAGE_SELF
doc update
placed all rusage variables into HAVE_GETRUSAGE block
updated to libopts 5.18.4
doc update
bumped version
Merge tag 'tags/gnutls_3_2_19'

released 3.2.19

# gpg: directory `/home/Matt/.gnupg' created
# gpg: new configuration file `/home/Matt/.gnupg/gpg.conf' created
# gpg: WARNING: options in `/home/Matt/.gnupg/gpg.conf' are not yet active during this run
# gpg: keyring `/home/Matt/.gnupg/pubring.gpg' created
# gpg: Signature made 13 Oct 2014 15:17:34 AEDT using RSA key ID 9013B842
# gpg: Can't check signature: public key not found
Update VS project files for 3.2.19 update.