Feature/mbedtls (#84)

* try to import mbedtls and build it

* add stubs socket class

* some boilterplate, read and write function implemented

* more boilterplate / current error in handshake because no CA cert is setup

* add something so skip ca verification, can ws curl https://google.com !

* cleanup / close implemented

* tweak CMakefiles

* typo in include

* update readme

* disable unittests

third_party/mbedtls/programs/test/query_compile_time_config.c

@@ -0,0 +1,56 @@
+/*
+ *  Query the Mbed TLS compile time configuration
+ *
+ *  Copyright (C) 2018, Arm Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of Mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdio.h>
+#include <stdlib.h>
+#define mbedtls_printf       printf
+#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
+#endif
+
+#define USAGE                                                                \
+    "usage: %s <MBEDTLS_CONFIG>\n\n"                                         \
+    "This program takes one command line argument which corresponds to\n"    \
+    "the string representation of a Mbed TLS compile time configuration.\n"  \
+    "The value 0 will be returned if this configuration is defined in the\n" \
+    "Mbed TLS build and the macro expansion of that configuration will be\n" \
+    "printed (if any). Otherwise, 1 will be returned.\n"
+
+int query_config( const char *config );
+
+int main( int argc, char *argv[] )
+{
+    if ( argc != 2 )
+    {
+        mbedtls_printf( USAGE, argv[0] );
+        return( MBEDTLS_EXIT_FAILURE );
+    }
+
+    return( query_config( argv[1] ) );
+}