ItEr47S04ValidacionEProbasFuncionaisItEr46S04: Avoiding first day gives zero hours for splines interpolation.

For each day the accumulated hours are the hours accumulated until
that day included. Before this commit the hours of that day were not
included.

navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/StretchesFunction.java

@@ -141,7 +141,7 @@ public class StretchesFunction extends AssignmentFunction {
             int[] result = new int[Days.daysBetween(startInclusive,
                     endExclusive).getDays()];
             for (int i = 0; i < result.length; i++) {
-                result[i] = evaluate(accumulatedFunction, i);
+                result[i] = evaluate(accumulatedFunction, i + 1);
             }
             return result;
         }