Integrate platform-specific presentation customizations with the build process.

[a-laughlin]

Architecture:
The build process should know nothing about the presentation. That way we can eventually shift to a native Android UI by switching which presentation parts we use, without having to change the plugins themselves.

Utils folders:
Each type of plugin (e.g., forms) will get its own utils folder specific to each presentation platform. So there is an Angular form utils folder for displaying the form as HTML. It contains html partials, css, and js files. Eventually there will be an Android form utils folder for displaying the form in Android.

Plugin folders:
Each form plugin itself should only contain a happathon.json file which which references the form parts in the form-utils folder. (I need to finish changing all the references from "happathon" to "inside". This ticket needs to be updated also afterward).

How to integrate:
How to get the css and js to run without the build process knowing about them... placing it in the utils plugin's json config would work. I don't have a config json specced for utils plugins yet though. Need to create that.