polarssl: fix compilation

Rename x509_cert to x509_crt and add "compat-1.2.h"
include.
This would still need some more thorough conversion
in order to drop "compat-1.2.h" include.
polarssl: now require 1.3.0+

Also fixed a function name change in the version requirement bump
polarssl: added missing end-of-comment from previous commit
polarssl: drop use of 1.2 compatibility header.

API has changed since version 1.3. A compatibility header has been created
to ensure forward compatibility for code using old API:
 * x509 certificate structure has been renamed to from x509_cert to
   x509_crt
 * new dedicated setter for RSA certificates ssl_set_own_cert_rsa,
   ssl_set_own_cert is for generic keys
 * ssl_default_ciphersuites has been replaced by function
   ssl_list_ciphersuites()

This patch drops the use of the compatibly header.
polarssl: break compatibility with version older than 1.3.

Remove all #ifdef/else/endif macros that ensure compatibility with polarssl
version previous than 1.3.
polarssl: fix possible handshake timeout issue in multi.

Because of the socket is unblocking, PolarSSL does need call to getsock to
get the action to perform in multi environment.

In some cases, it might happen we have not received yet all data to perform
the handshake. ssh_handshake returns POLARSSL_ERR_NET_WANT_READ, the state
is updated but because of the getsock has not the proper #define macro to,
the library never prevents to select socket for input thus the socket will
never be awaken when last data is available. Thus it leads to timeout.
RELEASE-NOTES: synced with 47f8e99e78c
trynextip: don't store 'ai' on failed connects...

It leads to the "next family" tries starting from the wrong point and thus
fails!

Bug: http://curl.haxx.se/bug/view.cgi?id=1337
Reported-by: ricker