[WIP] gulp-sourcemaps  support

Trying to support [floridoo/gulp-sourcemaps](https://github.com/floridoo/gulp-sourcemaps)

ref.[Plugins with gulp sourcemaps support](https://github.com/floridoo/gulp-sourcemaps/wiki/Plugins-with-gulp-sourcemaps-support)

- [x] add vinyl-sourcemaps-apply to dependencies
- [x] add multi-stage-sourcemap to dependencies
- [x] use espower directly
- [ ] maint tests
- [ ] refactor