Add maven support for bitcoinj.
Add maven support for bitcoinj.

After this CL, you can use "mvn install" to build / test the project.

git-svn-id: 222f534b05ab2d99128b129c3f2ba69c893481ce@90 a743e126-8abc-4207-e589-8f9b47be99bf

xmt/BitcoinJ