* 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
These certificates form a very long chain, used to test the
MBEDTLS_X509_MAX_INT_CA limit.
NN.key is the private key of certificate NN.crt.
The root is 00.crt and N+1.crt is a child of N.crt.
File cNN.pem contains the chain NN.crt to 00.crt.
Those certificates were generated by tests/data_files/dir-maxpath/long.sh.