Make str/str8 comparisons return True/False for !=/==.

Code that has been returning str8 becomes much more apparent thanks to this
(e.g., struct module returning str8 for all string-related formats or sqlite3
passing in str8 instances when converting objects that had a __conform__
method).  One also has to watch out in C code when making a key from char *
using PyString in the C code but a str instance in Python code as that will not
longer compare equal.

Once str8 gains a constructor like the current bytes type then
test_modulefinder needs a cleanup as the fix is a little messy in that file.

Thanks goes to Thomas Lee for writing the patch for the change giving an
initial run-down of why most of the tests were failing.

Lib/sqlite3/test/types.py

@@ -76,6 +76,10 @@ class SqliteTypeTests(unittest.TestCase):
 class DeclTypesTests(unittest.TestCase):
     class Foo:
         def __init__(self, _val):
+            if isinstance(_val, str8):
+                # sqlite3 always calls __init__ with a str8 created from a
+                # UTF-8 string when __conform__ was used to store the object.
+                _val = _val.decode('utf8')
             self.val = _val
 
         def __cmp__(self, other):