Pass connection options via command line

[IlyaSemenov]

Please allow to pass the database name and other connection options via command line or environmental variables rather, not only reading them from hard-coded path ./database.json.

This will greatly help in reusing the tool in automation scripts.

[jordanh]

We ended up creating a wrapper shellscript to achieve just this. You're welcome to it if you like!

[IlyaSemenov]

@jordanh thanks, from your wrapper I learned that it's actually possible to use --host, --port and --db.

I believe these options need to be documented and listed in --help.