Student Scheduling: Day of week offset

- added ability to set the day of week offset on an online section
- this is to make sure that the isEnabled(Student) checking computes the first/last meeting correctly during wait-list processing

src/org/cpsolver/studentsct/online/OnlineSection.java

@@ -34,6 +34,7 @@
 public class OnlineSection extends Section {
     private int iEnrollment = 0;
     private boolean iAlwaysEnabled = false;
+    private Integer iDayOfWeekOffset = null;
 
     public OnlineSection(long id, int limit, String name, Subpart subpart, Placement placement, List<Instructor> instructors, Section parent) {
         super(id, limit, name, subpart, placement, instructors, parent);
@@ -71,4 +72,13 @@ public boolean isEnabled(Student student) {
         return super.isEnabled(student);
     }
 
+    @Override
+    protected int getDayOfWeekOffset() {
+        if (iDayOfWeekOffset != null) return iDayOfWeekOffset;
+        return super.getDayOfWeekOffset();
+    }
+    public void setDayOfWeekOffset(Integer dayOfWeekOffset) {
+        iDayOfWeekOffset = dayOfWeekOffset;
+    }
+
 }