There is a bug in KeyRange split

[tanglizhe1105]

like KeyRange.linearSplit(), if param hostNum large than KeyRange.size(), the elem of sets whose index equal or more than KeyRange.size() will be invalid, since it's start is greater than end.

this will lead to disaster when initial storage for Keys, like IntArrayStore.init(), the Keys.size() will be negtive.

I have repaired this bug, and have pulled requests

maybe there is also similar problem in hashSplit, just i guess