Transactions debugged and renamed

Database creation function reworked to make primary key (int) fields for
each table.  Made compatible with mysql (hopefully- not yet tested.)
EconWrapper now has a pay method that takes money and item amounts and
logs the transaction automatically.  Some methods renamed so pay() is
not overloaded.
(/townadmin payTest) added to test the new pay funciton.
The rest of the changes are refactors due to Transactions.java being
renamed to Transaction.java, and from the method re-naming.