Hello antmail:

Thanks for adding these patches. I have a few places
in my tracker (sysadmin) where integer only values
would be very useful.

However it looks like you forgot to diff the tests directory as
I don't see any changes to the tests. I assume you duplicated
the tests for Number to use the Integer class and verified that
they all pass. Those changes should be part of the patch as well.

Also on your patch you left a pdb load/call in there.
I also saw some whitepsace only changes that should be
be cleaned up.

Bernhard, any idea what docs need to be updated?

At least the docs/customizing.txt section on:

   Properties

should be updated to include Integer.

Also docs/FAQ.txt section on:

    How is sorting performed, and why does it seem to fail sometimes?

need to include integer sorting.

I think design.txt should stay as is since it's
a historic file and not current documentation.

antmail, can you fix these and post a new patch.
Then I'll work on applying the patch to the mainine code.