--verbose flag

[nickbalestra]

At the moment, when packaging the data provider webpack will output some info to the terminal following the setting:

stats: {
    chunks: false,
    colors: true,
    version: false,
    hash: false
  }

Although pretty minimal, I can see how this could be annoying when working on data providers that simply deal with jade/handlebar templateEngines.
That output is instead very useful when working on modern view provider that will be handled by react or similar templateEngines... Because of this, I suggest we add a --verbose flag option on the dev command to output extra bundling info while muting it by default (stats: 'errors-only'). This flag could be then also passed to the templateEngine...