Simplify plugin system and improve bootstrap integration

* Switch from "module.class" to "plugin"
  * Change store model
  * Fix all plugins to be compatible
  * Fix CLI to support
  * Fix admin page

* Add bootstrap datatable integration
  * Include extra JS and CSS
  * Modify table generation

* Ensure all admin sections are in containers

* Correct RRD_DIR for stats graph (fixes #10)