+ Issue with OutOfMemory exception on download is now fixed;
+ Persistence Service now takes care for saving and retrieving data from
the database;
+ RemoteDataRetrieval Service now takes care for downloading content
from the remote server (ANGEL);
+ Now there are DB tables for sections and for the section-to-student
relationship;
+ DB is now only accessed through the Persistence Service class;
+ Cleared up unnecessary classes from the domain model