Add sensible defaults for LOCAL 'production' environment (Asset Pipeline)

[xarisd]

• Use gems 'figaro' and 'wannabe_bool' for setting ENV variables from a file (config/application.yml)
• Change 'config/environments/production.rb' to include an environment variable that switches on/off if assets will be served from Rails or not.
• Create a sample file 'config/application.example.yml' for easy reference
• Create a simple rake task 'rake dev:prepare:production_local' for automatically generate an application.yml file