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/doxygen/input/doc_hashing.h

@@ -0,0 +1,44 @@
+/**
+ * \file doc_hashing.h
+ *
+ * \brief Hashing module documentation file.
+ */
+/*
+ *
+ *  Copyright (C) 2006-2015, 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)
+ */
+
+/**
+ * @addtogroup hashing_module Hashing module
+ *
+ * The Message Digest (MD) or Hashing module provides one-way hashing
+ * functions. Such functions can be used for creating a hash message
+ * authentication code (HMAC) when sending a message. Such a HMAC can be used
+ * in combination with a private key for authentication, which is a message
+ * integrity control.
+ *
+ * All hash algorithms can be accessed via the generic MD layer (see
+ * \c mbedtls_md_setup())
+ *
+ * The following hashing-algorithms are provided:
+ * - MD2, MD4, MD5 128-bit one-way hash functions by Ron Rivest.
+ * - SHA-1, SHA-256, SHA-384/512 160-bit or more one-way hash functions by
+ *   NIST and NSA.
+ *
+ * This module provides one-way hashing which can be used for authentication.
+ */