Unsafe in a multi-DC environment

[BrianGallew]

Ranges for repairs need to be calculated against tokens held by local DC ring members only. Currently, if you have a situation like this:
DC1: nodeA(1), nodeB(3)
DC2: nodeC(2), nodeD(4)

running this script on nodeA will result in repairs of the range (1,2), which is insufficient for the needs of the local DC.

I originally opened this as mstump#3 but that repo is really dead.