Refactor configuration

- No longer use config npm package
- Prefer config from env vars, though still has support for config file
- No longer writes a config file for database config
- Writes keys to a new file in /data folder
- Removes a lot of cruft and improves config understanding

backend/lib/validator/index.js

@@ -5,7 +5,7 @@ const definitions = require('../../schema/definitions.json');
 RegExp.prototype.toJSON = RegExp.prototype.toString;
 
 const ajv = require('ajv')({
-	verbose:     true, //process.env.NODE_ENV === 'development',
+	verbose:     true,
 	allErrors:   true,
 	format:      'full',  // strict regexes for format checks
 	coerceTypes: true,