Add a removeEventListener method. Idea from Andreas. Resolves issue 27.
Add a removeEventListener method. Idea from Andreas. Resolves issue 27.

git-svn-id: 222f534b05ab2d99128b129c3f2ba69c893481ce@126 a743e126-8abc-4207-e589-8f9b47be99bf

xmt/BitcoinJ