Changed the objective function from medianDR to meanDR. DR stands for discrimination ratio.
The following edits were made:

1. Return function was changed to include the bestsolution found in the run and the best schedule found.
2. The objective function was changed from medianDR to meanDR. DR stands for discrimination ratio. It is the ratio of intra-sessionsimilarity to inter-sessionsimilarity for a schedule
3. An unused function was removed.
4. A few function names were changed.