algebra-4.2: CHANGELOG.markdown

4.2
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* Support for `nats` version 1 and `base` 4.8's version of `Numeric.Natural`. This required monomorphizing some stuff to `Natural`, but that is more accurate than the previous hack anyways.

4.1
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* Added Euclidean domains and the field of fractions.

4.0
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* Compatibility with GHC 7.8.x
* Removed `keyed` and `representable-tries` dependencies

3.0.2
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* Started CHANGELOG