Feature Request: Reporters

[shellscape]

I'd like to request the ability to use reporters akin to what gulp-jshint and gulp-recess currently allow. While emitting a PluginError is helpful, concatenating all of the encountered errors into one bucket and allowing a reporter to operate on that for meaningful/formatted feedback to the user would be pretty dang great.

[lazd]

I'm not sure this will be a common request as usually a broken template is a fatal error for most use cases. As this isn't a linting tool (it's pass or fail), reporters may not have a place directly in the plugin itself. However, a code sample here or an example in the repo wouldn't hurt.

What do you think?

[shellscape]

A code sample is better than nothing. I'm of the opinion that even non-linting plugins/tasks can make use of the reporting model.