Initial python3 changes

Mostly just updating libraries, removing string encoding/decoding,
fixing some edge cases. No new functionality was added in this
commit.

lib/cheroot/test/conftest.py

@@ -0,0 +1,71 @@
+"""Pytest configuration module.
+
+Contains fixtures, which are tightly bound to the Cheroot framework
+itself, useless for end-users' app testing.
+"""
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type  # pylint: disable=invalid-name
+
+import threading
+import time
+
+import pytest
+
+from ..server import Gateway, HTTPServer
+from ..testing import (  # noqa: F401  # pylint: disable=unused-import
+    native_server, wsgi_server,
+)
+from ..testing import get_server_client
+
+
+@pytest.fixture
+# pylint: disable=redefined-outer-name
+def wsgi_server_client(wsgi_server):  # noqa: F811
+    """Create a test client out of given WSGI server."""
+    return get_server_client(wsgi_server)
+
+
+@pytest.fixture
+# pylint: disable=redefined-outer-name
+def native_server_client(native_server):  # noqa: F811
+    """Create a test client out of given HTTP server."""
+    return get_server_client(native_server)
+
+
+@pytest.fixture
+def http_server():
+    """Provision a server creator as a fixture."""
+    def start_srv():
+        bind_addr = yield
+        if bind_addr is None:
+            return
+        httpserver = make_http_server(bind_addr)
+        yield httpserver
+        yield httpserver
+
+    srv_creator = iter(start_srv())
+    next(srv_creator)  # pylint: disable=stop-iteration-return
+    yield srv_creator
+    try:
+        while True:
+            httpserver = next(srv_creator)
+            if httpserver is not None:
+                httpserver.stop()
+    except StopIteration:
+        pass
+
+
+def make_http_server(bind_addr):
+    """Create and start an HTTP server bound to ``bind_addr``."""
+    httpserver = HTTPServer(
+        bind_addr=bind_addr,
+        gateway=Gateway,
+    )
+
+    threading.Thread(target=httpserver.safe_start).start()
+
+    while not httpserver.ready:
+        time.sleep(0.1)
+
+    return httpserver