@phated Could you review this pr, too?

To fix the issue: gulp-cli #181, I was going to modify to export registerLoader of liftoff and use it like this.

However I've noticed that this pr can achieve to fix gulp-cli #181 with the modification of gulp-cli like:

(gulp-cli/index.js)
cli.prepareConfig = function(env, opts) {
  var cfgLoadOrder = ['home', 'cwd'];
  var cfg = loadConfigFiles(env.configFiles['.gulp'], cfgLoadOrder);
  opts = mergeConfigToCliFlags(opts, cfg);
  env = mergeConfigToEnvFlags(env, cfg);

  Liftoff.prototype.prepareConfig(env, opts);

};

I've rebased and made a couple of changes to this PR.

Closed by 6e280ae

Thanks for all the work on this stuff @sttk and I apologize for delaying review for so long!

@sttk Do you think the 2 changes you made are fine to be released as version 2.5.1 or should I do 2.6.0?