Changed from extending AbstractEconomy to implementing Economy to
account for uuid update.
Deprecated string methods in EconomyManager.
Added convenience method for getting FinancialInstitutions by name.
Fixing exception errors by throwing them up the path.
Moved methods of LoanLenderHandler back to LoanHandler. Improved
comments on loanOfferingCommand(...) and sendOffer(...) command. Still
need to finish sendOffer.