[squeak-dev] [trunk] fix closeTo:

As a simple experiment,
    Kernel-nice.193 + KernelTests-nice.70
have tests + fixes for closeTo: from
    http://bugs.squeak.org/view.php?id=6729
    http://bugs.squeak.org/view.php?id=7368

This is essentially:
    Installer mantis ensureFix: 7368.

Nicolas