When checking for data to be received use the 'transport_recv_ptr'

This affects cases where there is different send and recv pointers.
Reported and investigated by JMRecio.
doc update
Both DANE and PKI verification are advisory when --tofu is being used.
Made _gnutls_get_auth_info() safer to use.
_gnutls_auth_info_set() will decide the replacing of auth info based on the provided credentials type.

This avoids issues with discrepances in server and client mode.
eliminated the leak of hint when deallocating the credentials.
use custom proc_server_kx for RSA-PSK
Enable hint in the rsa-psk test.
Avoid dual generation of key.
include hint into psk test.
corrected get_auth_info() for SRP-RSA.
doc update
doc update
fix typo
Use a harder to optimize out memset().
Removed the already unused secure alloc functions.
fix issue in gnutls_subject_alt_names_get().

That caused a null pointer dereference when extracting names
from a certificate that contained an OtherName. Reported and
investigated by Kirill A. Shutemov.
doc update
increased server startup wait time.

That is because we now check for key/certificate match via a sign/verify
request that may take longer in some systems. Based on patch by Andreas
Metzler.
copy_string() and copy_data() are more resilient on null input