Allow disabling of Validation#flatMap deprecation warning by `import Validation.FlatMap._`.
IList.fill test
optimize IList.fill
Merge pull request #637 from S11001001/topic/validation-flatmap-optdeprecate

Allow disabling of Validation#flatMap deprecation warning
optimize IList#span, splitAt, takeWhile
Setting version to 7.1.0-M5
Setting version to 7.1.0-SNAPSHOT