Bug fixed: Price and amount of offers were not correct.
Cancelled and empty auctions are differentiated.

The auctions cancelled due to lack of production are differentiated from
the auctions that do not receive any offer.
Added ProductionAssigner in different classes (files).

Each ProductionAssigner is coded in its own class. The instantiated
class is configured through the Injection utils.
Change on the comments (minor change).
Items of the AuctionBoard implements Comparable.
Replaced static store by a singleton on in CronLevelSchedule.
Added ProductionAssigner in different classes for Exp04.

Each ProductionAssigner is coded in its own class. The instantiated
class is configured through the Injection utils.
Add to the log the non-accepted offers.
Refactored tests of Exp03.

The tests corresponding to the experiment 03 are refactored, so that all
the initiation of the platform components is grouped in one routine.
Moreover, the initiation of the platform is always carried out after the
last change to the Injection module.