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/tests/git-scripts/README.md

@@ -0,0 +1,16 @@
+README for git hooks script
+===========================
+git has a way to run scripts, which are invoked by specific git commands.
+The git hooks are located in `<mbed TLS root>/.git/hooks`, and as such are not under version control
+for more information, see the [git documentation](https://git-scm.com/docs/githooks).
+
+The mbed TLS git hooks are located in `<mbed TLS root>/tests/git-scripts` directory, and one must create a soft link from `<mbed TLS root>/.git/hooks` to `<mbed TLS root>/tesst/git-scripts`, in order to make the hook scripts successfully work.
+
+Example:
+
+Execute the following command to create a link on linux from the mbed TLS `.git/hooks` directory:  
+`ln -s ../../tests/git-scripts/pre-push.sh pre-push`
+
+**Note: Currently the mbed TLS git hooks work only on a GNU platform. If using a non-GNU platform, don't enable these hooks!**
+
+These scripts can also be used independently.