Version 4.15.2

Set version to 4.15.1

[ci skip]

Update change log

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Add cabal.project to address issue ekmett#652

Remove internal voids and skips finishing 3a8a24d

Set version to 4.13.2, update changelog

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version 4.13.1 [ci skip]

version 4.13

Use "simpler" type synonyms where possible

Fixes ekmett#575

start a 4.12.2 CHANGELOG