Merge pull request #7 from rajbot/master

Add documentation on modify_metadata().
Moved command line script back to bin.
Renamed command line script to ia
Merge branch 'master' of github.com:jjjake/ia-wrapper
Simplified main execution
update README.md with installation instructions and CLI tool usage.
Merge branch 'master' of https://github.com/jjjake/ia-wrapper