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/include/CMakeLists.txt

@@ -0,0 +1,16 @@
+option(INSTALL_MBEDTLS_HEADERS "Install mbed TLS headers." ON)
+
+if(INSTALL_MBEDTLS_HEADERS)
+
+    file(GLOB headers "mbedtls/*.h")
+
+    install(FILES ${headers}
+        DESTINATION include/mbedtls
+        PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
+
+endif(INSTALL_MBEDTLS_HEADERS)
+
+# Make config.h available in an out-of-source build. ssl-opt.sh requires it.
+if (NOT ${CMAKE_CURRENT_BINARY_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+    link_to_source(mbedtls)
+endif()