Update the code to better reflect recommended style:

Use != instead of <> since <> is documented as "obsolescent".
Use "is" and "is not" when comparing with None or type objects.
diff --git a/Lib/lib-old/cmpcache.py b/Lib/lib-old/cmpcache.py
index 93332b7..11540f8 100644
--- a/Lib/lib-old/cmpcache.py
+++ b/Lib/lib-old/cmpcache.py
@@ -30,7 +30,7 @@
     if shallow and s1 == s2:
         # type, size & mtime match -- report same
         return 1
-    if s1[:2] <> s2[:2]: # Types or sizes differ, don't bother
+    if s1[:2] != s2[:2]: # Types or sizes differ, don't bother
         # types or sizes differ -- report different
         return 0
     # same type and size -- look in the cache
@@ -60,5 +60,5 @@
     while 1:
         b1 = fp1.read(bufsize)
         b2 = fp2.read(bufsize)
-        if b1 <> b2: return 0
+        if b1 != b2: return 0
         if not b1: return 1