Log Message:
devel/hs-QuickCheck: Update to 2.15

QuickCheck 2.15
	* BREAKING: properties without quantification are no longer implicitly
	  wrapped in once
	* Add witness property modifier and witnesses field in result on
	compilers that support Typeable to allow conveniently exposing
	counterexamples
	* Add assertException, assertExceptionIO, assertDeepException, and
	assertDeepExceptionIO (thanks to Alexey Kuleshevich)
	* Add withMaxSize, withMaxShrinks, and withMaxDiscardRatio combinators
	* Add recheck
	* Add HasCallStack to partial top-level functions
	* Updated some documentation
	* Fix overflow bug when calculating discard ratio
	* Fix error printing bug when shrinks are discarded
	* Fix withMaxSuccess not working when checkCoverage is turned on
	* Fix a bug whereby an unfortunately timed discard could unduly fail a
	property running with checkCoverage
	* Fix Arbitrary intance for Map breaking invariants from
	Data.Map.Strict (thanks to Neil Mayhew)
	* Fix non-covered classes not showing up in output as 0% covered
	* Fix Negative's Arbitrary instance discarding an unnecessary number
	of generated values.
	* Fix promote doing an unnecessary seed split
	* Fix a bug whereby maxSuccess and discardRatio would interact poorly
	to produce too few size increases.
	* Fix a couple of underflow bugs in generators for Small Natural and
	Ratio Natural
	* Fix a bug whereby the internal DISCARDED exception would show up
	user-side in sample