Added checks for integer overflows, contributed by Google. Some are
 only available if asserts are left in the code, in cases where they
 can't be triggered from Python code.

Document the new 'offset' parameter for the 'ctypes.byref' function.

stringobject and PyBytes defines in bytesobject.

I had to disable one test because it was functioning incorrectly, see #1530559
I also removed the debugging prints

* Convert binary methods in Integral to mixin methods
* Remove three-arg __pow__ as a required method
* Make __int__ the root method instead of __long__.

C:\temp => file:///C|temp/

Part of reverting most of r63675 per the mailing list discussion.

occurances of PyBytes_ in the code to their original PyString_ names.  The
bytesobject.c file will be renamed back to stringobject.c in a future checkin.

NameErrors pointed out by Giampaolo.

Add an optional 'offset' parameter to byref, defaulting to zero.

issues in: 909005 and 17361001, as well as completely as possible issues
539444, 760475, 777588, 889153, 953599, 1025525, 1063924, and 658749.
This patch also includes doc and test updates as necessary.

Cleaned up the unit test.