Add Autobahn test suite for websockets

We're using the existing test suite for websocket servers from the
Autobahn project to verify that out websockets implementation is
sane. A CT test suite and python module wrapping the test suite has
been added. The test suite is run when the 'make inttests' target
is executed.

test/autobahn_SUITE_data/test.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python
+import os
+import os.path
+import sys
+import subprocess
+
+
+AB_TESTS_ENV = os.getenv("AB_TESTS_ENV")
+AB_TESTS_PRIV = os.getenv("AB_TESTS_PRIV")
+
+VIRTUALENV_URL = 'https://raw.github.com/pypa/virtualenv/master/virtualenv.py'
+VIRTUALENV_BIN = os.path.join(AB_TESTS_ENV, "virtualenv.py")
+PIP_BIN = os.path.join(AB_TESTS_ENV, "bin", "pip")
+
+
+def activate_env(env):
+    """
+    See 'Using Virtualenv without bin/python' at http://www.virtualenv.org
+    """
+    activate_this = os.path.join(env, 'bin', 'activate_this.py')
+    exec(compile(open(activate_this).read(), activate_this, 'exec'),
+        dict(__file__=activate_this))
+
+def install_env(env):
+    """
+    Install a new virtualenv at a path and also install the Autobahn package.
+    """
+    os.makedirs(env) if not os.path.isdir(env) else None
+    subprocess.check_call(["curl", "-sS", VIRTUALENV_URL, "-o", VIRTUALENV_BIN])
+    subprocess.check_call(["python", VIRTUALENV_BIN, env])
+    activate_env(env)
+    subprocess.check_call([PIP_BIN, "install", "Autobahn"])
+
+def client_config():
+    """
+    See comment on SUPPORTED_SPEC_VERSIONS in Autobahn/.../websocket.py
+    """
+    base = {
+        'options': {'failByDrop': False},
+        'enable-ssl': False,
+        'servers': [{
+             'agent': 'Cowboy/10',
+             'url': 'ws://localhost:33080/echo',
+             'options': {'version': 10}}, # hybi-10
+            {'agent': 'Cowboy/18',
+             'url': 'ws://localhost:33080/echo',
+             'options': {'version': 18}} # RFC6455
+        ],
+        'cases': ['*'],
+        'exclude-cases': [] }
+    return base
+
+def run_test(env, config):
+    activate_env(env)
+    from twisted.python import log
+    from twisted.internet import reactor
+    from autobahn.fuzzing import FuzzingClientFactory
+    os.chdir(AB_TESTS_PRIV)
+    log.startLogging(sys.stdout)
+    fuzzer = FuzzingClientFactory(config)
+    return reactor.run()
+
+
+def main():
+    cmd = sys.argv[1]
+    if cmd == 'setup':
+        install_env(AB_TESTS_ENV)
+        print('AB-TESTS-SETUP-OK')
+    elif cmd == 'test':
+        run_test(AB_TESTS_ENV, client_config())
+        print('AB-TESTS-TEST-OK')
+    else:
+        return 1
+
+if __name__ == '__main__':
+    main()