docker.tough-rate

This new version of (docker.)tough-rate uses:

• useful-wind, the generic FreeSwitch middleware router and call-server, based on the esl FreeSwitch socket API for Node.js;
• thinkable-ducks, the generic FreeSwitch image that supports useful-wind;
• tough-rate, the Node.js LCR engine (which now uses useful-wind);
• and the present code (middelware/* and a Dockerfile), which provides CCNQ4 database adaptation and then hands it off to thinkable-ducks.