pldi2011 testcases moved to proper directory

testcases/verification/compilation/ForElimination.scala

testcases/verification/compilation/LambdaEval.scala

...ases/verification/compilation/SemanticsPreservation.scala

testcases/verification/datastructures/ListTree.scala

testcases/verification/datastructures/QuickSort.scala

...es/verification/datastructures/RedBlackTreeDeletion.scala

...s/verification/datastructures/RedBlackTreeWithOrder.scala

testcases/verification/datastructures/TreeMap.scala

testcases/verification/list-algorithms/InsertionSort.scala

...ses/verification/pldi2011-testcases/AssociativeList.scala

...cases/verification/pldi2011-testcases/InsertionSort.scala

testcases/verification/pldi2011-testcases/MergeSort.scala

.../verification/pldi2011-testcases/PropositionalLogic.scala

testcases/verification/pldi2011-testcases/QuickSort.scala