Make a new urllib package .

It consists of code from urllib, urllib2, urlparse, and robotparser.
The old modules have all been removed.  The new package has five
submodules: urllib.parse, urllib.request, urllib.response,
urllib.error, and urllib.robotparser.  The urllib.request.urlopen()
function uses the url opener from urllib2.

Note that the unittests have not been renamed for the
beta, but they will be renamed in the future.

Joint work with Senthil Kumaran.

Lib/urllib/response.py

@@ -0,0 +1,83 @@
+"""Response classes used by urllib.
+
+The base class, addbase, defines a minimal file-like interface,
+including read() and readline().  The typical response object is an
+addinfourl instance, which defines an info() method that returns
+headers and a geturl() method that returns the url.
+"""
+
+class addbase(object):
+    """Base class for addinfo and addclosehook."""
+
+    # XXX Add a method to expose the timeout on the underlying socket?
+
+    def __init__(self, fp):
+        # TODO(jhylton): Is there a better way to delegate using io?
+        self.fp = fp
+        self.read = self.fp.read
+        self.readline = self.fp.readline
+        # TODO(jhylton): Make sure an object with readlines() is also iterable
+        if hasattr(self.fp, "readlines"): self.readlines = self.fp.readlines
+        if hasattr(self.fp, "fileno"):
+            self.fileno = self.fp.fileno
+        else:
+            self.fileno = lambda: None
+        if hasattr(self.fp, "__iter__"):
+            self.__iter__ = self.fp.__iter__
+            if hasattr(self.fp, "__next__"):
+                self.__next__ = self.fp.__next__
+
+    def __repr__(self):
+        return '<%s at %r whose fp = %r>' % (self.__class__.__name__,
+                                             id(self), self.fp)
+
+    def close(self):
+        self.read = None
+        self.readline = None
+        self.readlines = None
+        self.fileno = None
+        if self.fp: self.fp.close()
+        self.fp = None
+
+class addclosehook(addbase):
+    """Class to add a close hook to an open file."""
+
+    def __init__(self, fp, closehook, *hookargs):
+        addbase.__init__(self, fp)
+        self.closehook = closehook
+        self.hookargs = hookargs
+
+    def close(self):
+        addbase.close(self)
+        if self.closehook:
+            self.closehook(*self.hookargs)
+            self.closehook = None
+            self.hookargs = None
+
+class addinfo(addbase):
+    """class to add an info() method to an open file."""
+
+    def __init__(self, fp, headers):
+        addbase.__init__(self, fp)
+        self.headers = headers
+
+    def info(self):
+        return self.headers
+
+class addinfourl(addbase):
+    """class to add info() and geturl() methods to an open file."""
+
+    def __init__(self, fp, headers, url, code=None):
+        addbase.__init__(self, fp)
+        self.headers = headers
+        self.url = url
+        self.code = code
+
+    def info(self):
+        return self.headers
+
+    def getcode(self):
+        return self.code
+
+    def geturl(self):
+        return self.url