Add comments to the code

Signed-off-by: Gustavo L. de M. Chaves <gnustavo@cpan.org>
Implement the 'backout' command

Signed-off-by: Gustavo L. de M. Chaves <gnustavo@cpan.org>
Change 'query' output format

Signed-off-by: Gustavo L. de M. Chaves <gnustavo@cpan.org>
Refactor 'push'

Signed-off-by: Gustavo L. de M. Chaves <gnustavo@cpan.org>