Replace OpenSSL with PolarSSL

Works on windows, not yet cmake.

Externals/polarssl/doxygen/input/doc_tcpip.h

@@ -0,0 +1,26 @@
+/**
+ * @file
+ * TCP/IP communication module documentation file.
+ */
+
+/**
+ * @addtogroup tcpip_communication_module TCP/IP communication module
+ * 
+ * The TCP/IP communication module provides for a channel of
+ * communication for the \link ssltls_communication_module SSL/TLS communication 
+ * module\endlink to use. 
+ * In the TCP/IP-model it provides for communication up to the Transport 
+ * (or Host-to-host) layer. 
+ * SSL/TLS resides on top of that, in the Application layer, and makes use of
+ * its basic provisions:
+ * - listening on a port (see \c net_bind()).
+ * - accepting a connection (through \c net_accept()).
+ * - read/write (through \c net_recv()/\c net_send()).
+ * - close a connection (through \c net_close()).
+ *
+ * This way you have the means to, for example, implement and use an UDP or 
+ * IPSec communication solution as a basis.
+ * 
+ * This module can be used at server- and clientside to provide a basic
+ * means of communication over the internet.
+ */