merge of features from hosted branch (#7)

major merge of features from the hosted branch that was created temporarily during the initial launch of jambonz.org

lib/db/pool.js

@@ -0,0 +1,10 @@
+const mysql = require('mysql2');
+const pool = mysql.createPool({
+  host: process.env.JAMBONES_MYSQL_HOST,
+  port: process.env.JAMBONES_MYSQL_PORT || 3306,
+  user: process.env.JAMBONES_MYSQL_USER,
+  password: process.env.JAMBONES_MYSQL_PASSWORD,
+  database: process.env.JAMBONES_MYSQL_DATABASE,
+  connectionLimit: process.env.JAMBONES_MYSQL_CONNECTION_LIMIT || 10
+});
+module.exports = pool.promise();