Update DB scheme, added a message for expl.

DB Scheme has been changed for better integration. Addition of a
message for explanation. The manager will be the one taking care of
everythingUpdate DB scheme, added a message for expl.
Adding calls for DB in Manager, new controls

Adding controls to delete a research (cascade). Everything now passes
through the Manager, which would be extended to be the only statefull
part fo the program if required.