The MultiBit build

Proposed improvements to the build:

• make the maven POM.XML a bit cleaner - see the maven_todo.txt in the project top level directory.
• ring fence the Wallet code into a 'wallet1' src tree with backwards compatibility tests to ensure MultiBit 0.1.x and 0.2.x wallets are always readable in the future.
• simplify the logging, which is two systems bolted together.
• get back to the head of bitcoinj, remove copy of code from MultiBit
• provide Mike patch for pending transactions
• provide Mike patch for basic fee support