findLeaves() shortened, and TestFindLeaves()
shorter encoding of before/after map test cases
more TestPlanNextMapVis helper vars
test 2 unbalanced nodes to balanced'ness
test 8 partitions, 1 to 8 nodes
test 8 partitions, 1 to 8 nodes, 0 slaves
8 partition case stabilization tests
test single node swap rebalance
test 4 nodes to 3 nodes, remove node d
separate struct for VisTestCase
moved testVisTestCases() higher
try changing constraints
test 2 racks, but nil hierarchy rules
test 2 racks, favor same rack
fix topPriorityNode calc & test favor other rack for slave