Hello up there.

Recently with Ivan we needed a way to obtain last transaction ID of a ZODB storage for resiliency checking. For this zodb info utility to print general information about a ZODB database is introduced. Along the way, as it was already planned, all zodbtools utilities are now covered by only one zodb command which can invoke other subcommands and show help topics. I also used the occassion to switch how storages are specified from being ZConfig-file-always to be specified by URL e.g.

 neo://neo1@127.0.0.1:24573
 zeo://...
 file://...

without loosing generality because zconfig:// scheme is also supported.

Please find more details about all changes in individal commit messages.

Thanks for feedback,
Kirill

/cc @kazuhiko, @jm, @vpelletier, @jerome, @Tyagov, @klaus, @alain.takoudjou, @rafael