Change Rules structure to avoid duplicates.

Rename Rules.depts[DEPT][YEAR].program to Rules.depts[DEPT][YEAR].programs
Move depts[DEPT][YEAR].programs[PROG].equivalence to depts[DEPT].equivalence
  This is like global equivalence list. Local list can still be used if needed.
Move depts[DEPT][YEAR].programs[PROG].electives to depts[DEPT].electives
  This is like global electives list. Local list can still be used if needed.
Move Rules.depts[DEPT][YEAR] to Rules.depts[DEPT].years[YEAR]
Minor fixes.