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/crypto/doxygen/input/doc_mainpage.h

@@ -0,0 +1,49 @@
+/**
+ * \file doc_mainpage.h
+ *
+ * \brief Main page documentation file.
+ */
+/*
+ *
+ *  Copyright (C) 2006-2019, 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)
+ */
+
+/**
+ * @mainpage Mbed Crypto v0.1.0 source code documentation
+ *
+ * This documentation describes the internal structure of mbed TLS.  It was
+ * automatically generated from specially formatted comment blocks in
+ * mbed TLS's source code using Doxygen.  (See
+ * http://www.stack.nl/~dimitri/doxygen/ for more information on Doxygen)
+ *
+ * Mbed Crypto provides an implementation of the PSA Crypto API. The library is
+ * comprised of a number of independent modules, listed in the \ref
+ * mainpage_modules "Modules section". This "Modules section" introduces the
+ * high-level module concepts used throughout this documentation.
+ *
+ * @section mainpage_modules Modules
+ *
+ * Mbed Crypto provides the following modules:
+ * - Random number generation
+ * - Hashing
+ * - Encryption/decryption
+ *
+ * Above functions are split up neatly into logical interfaces. These can be
+ * used separately to provide any of the above functions or to mix-and-match.
+ *
+ */