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/tests/data_files/print_c.pl

@@ -0,0 +1,34 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+if (!@ARGV || $ARGV[0] == '--help') {
+    print <<EOF;
+Usage: $0 mbedtls_test_foo <file.pem
+       $0 TEST_FOO mbedtls_test_foo <file.pem
+Print out a PEM file as C code defining a string constant.
+
+Used to include some of the test data in /library/certs.c for
+self-tests and sample programs.
+EOF
+    exit;
+}
+
+my $pp_name = @ARGV > 1 ? shift @ARGV : undef;
+my $name = shift @ARGV;
+
+my @lines = map {chomp; s/([\\"])/\\$1/g; "\"$_\\r\\n\""} <STDIN>;
+
+if (defined $pp_name) {
+    foreach ("#define $pp_name", @lines[0..@lines-2]) {
+        printf "%-72s\\\n", $_;
+    }
+    print "$lines[@lines-1]\n";
+    print "const char $name\[\] = $pp_name;\n";
+} else {
+    print "const char $name\[\] =";
+    foreach (@lines) {
+        print "\n$_";
+    }
+    print ";\n";
+}