Fixed NeoStoreTransactionTest
NeoCommandVisitor has been renamed to NeoCommandHandler, and TransactionRepresentation now takes a Visitor<Command,IOException> instead. Reason being that handling specific commands is a special case of the visitor pattern, and so handlers can be implemented as a visitor, but the visitor also allows other usages that do not care about particular types of commands, such as collecting them up. It also allows for decoration pattern to be used later on.
Updated LICENSES.txt and NOTICE.txt
UDC dependency changed to proper module