[ENH] testing for almost equal numerical results

I added a SUnit method to be able to compare numerical values up to

a certain precision in unit tests.

This exist in PyUnit [1], so given I needed it, I added it in Squeak

Core developers, should you find it useful for the community, please include it in Trunk.

Thanks in advance

Bye

Enrico

[1] TestCase.assertAlmostEqual(first, second[, places[, msg]])
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Enrico Spinielli
"Do Androids dream of electric sheep?"— Philip K. Dick
"Hear and forget; see and remember;do and understand."—Mitchel Resnick