Compile All Contrib and Custom .js Files Into a Single .js File

[signalpoint]

Some apps can have lots of contrib modules and custom modules installed. Here's an example app's console.log() output during the bootstrap:

app/modules/addressfield/addressfield.js jdrupal-dev.min.js:7
app/modules/date/date.js jdrupal-dev.min.js:7
app/modules/entityreference/entityreference.js jdrupal-dev.min.js:7
app/modules/flag/flag.js jdrupal-dev.min.js:7
app/modules/fivestar/fivestar.js jdrupal-dev.min.js:7
app/modules/force_authentication/force_authentication.js jdrupal-dev.min.js:7
app/modules/link/link.js jdrupal-dev.min.js:7
app/modules/geofield/geofield.js jdrupal-dev.min.js:7
app/modules/rate/rate.js jdrupal-dev.min.js:7
app/modules/telephone/telephone.js jdrupal-dev.min.js:7
app/modules/webform/webform.js jdrupal-dev.min.js:7
app/modules/custom/my_module/my_module.js jdrupal-dev.min.js:7
themes/easystreet3/easystreet3.js

Each one of these has to be manually loaded into the DOM via a GET during the bootstrap. This definitely causes performance issues, and probably hogs more memory than necessary. It'd be great if we could optionally include a single file in the index.html file, for example:

<script type="text/javascript" "bin/drupalgap.js"></script>
<script type="text/javascript" "bin/drupalgap.aggregated.js"></script><!-- all custom/contrib modules in one file -->

So to do this we would need a command which would round up all the .js files that make up the app's custom/contrib modules, and concatenate them all into a single .js file and write it to the bin directory. For example:

dgm aggregate js

We then would need a corresponding entry for settings.js, for example:

drupalgap.settings.aggregations = {
  js: {
    enabled: true;
  },
  css: {
    enabled: false;
  }
};

Then DG core would need to be updated to skip the manual loading during the bootsrap if aggregation is turned on.

It'd be extra cool if the command could automatically add/delete the JS script inclusion from the index.html file and update the settings.js file. Maybe settings.yaml is a pre-requisite to such features.