For scala, using typesafe config, read default config and read runtime config if given via cmdline option

gistfile1.scala

/*
Prior to this, I would build up `cfgMap` from my command line options.  
If `'config` exists, that will load the run time config file and overlay it on top of the default config.
*/
    // setup our default config
    lazy val defaultConfig = ConfigFactory.parseResources("default.conf")
    var conf = defaultConfig

    // do we have a runtime config file?
    val cfgFilePath = cfgMap.getOrElse('config, Nil)
    if (cfgFilePath != Nil) {
      lazy val userConfig = ConfigFactory
        .parseFile(new File(cfgFilePath.toString))
      conf = userConfig.withFallback(defaultConfig)
    }
    conf = conf.resolve()