Fixing contracts

changed return type to Pair, changing contracts accordingly.

public/java/src/org/broadinstitute/sting/utils/sam/ReadUtils.java

@@ -825,7 +825,7 @@ public class ReadUtils {
      * @return the read coordinate corresponding to the requested reference coordinate. (see warning!)
      */
     @Requires({"refCoord >= read.getUnclippedStart()", "refCoord <= read.getUnclippedEnd()"})
-    @Ensures({"result >= 0", "result < read.getReadLength()"})
+    @Ensures({"result.getFirst() >= 0", "result.getFirst() < read.getReadLength()"})
     public static Pair<Integer, Boolean> getReadCoordinateForReferenceCoordinate(SAMRecord read, int refCoord) {
         int readBases = 0;
         int refBases = 0;