Add "no-log" modus to binary

[martinheidegger]

When starting the dht as a node it will automatically log requests

https://github.com/hyperswarm/dht/blob/153d0fb498cc8ba106e64ba23612e28ee250a447/bin.js#L11-L21

this might fill up the hard disc and it should be possible to switch it of.

Note: I am not sure how to implement this best, else I would send a PR

[davidmarkclements]

to implement:

• accept a flag on the command line (e.g. -q)
• const quiet = process.argv.indexOf('-q') > -1
• every log if (!quiet) console.log('blah')

[da2x]

This was resolved in #28.