Prepare a structure for plugins to register with

I believe I need to execute any code that plugins will need to hook into before the Rails initialize block in config/environment.rb (at the top of the file).

Ansuz::PluginManager will have an attr_accessor :plugins, :frontend_views, :backend_views, and each Ansuz plugin will need to register itself.

A plugin will provide modules. Each Frontend module will need an associated Backend module. For instance, a ContentSection will have a base Frontend module that just renders the ContentSection on the page, and an associated Backend module that allows one to modify the content.

A plugin's registration in init.rb could look something like this:

Ansuz::PluginManager.register_plugin(Ansuz::Plugins::JAdams::ContentSection)

...where Ansuz::Plugins::JAdams::ContentSection defines its Frontend modules and their related Backend modules.