Migrate as much as possible to pip and requirements.txt

lib/cherrypy/wsgiserver/__init__.py

@@ -1,14 +0,0 @@
-__all__ = ['HTTPRequest', 'HTTPConnection', 'HTTPServer',
-           'SizeCheckWrapper', 'KnownLengthRFile', 'ChunkedRFile',
-           'MaxSizeExceeded', 'NoSSLError', 'FatalSSLAlert',
-           'WorkerThread', 'ThreadPool', 'SSLAdapter',
-           'CherryPyWSGIServer',
-           'Gateway', 'WSGIGateway', 'WSGIGateway_10', 'WSGIGateway_u0',
-           'WSGIPathInfoDispatcher', 'get_ssl_adapter_class']
-
-import sys
-if sys.version_info < (3, 0):
-    from wsgiserver2 import *
-else:
-    # Le sigh. Boo for backward-incompatible syntax.
-    exec('from .wsgiserver3 import *')