Add District#color and District#full_name to DRY-up layer render

Conflicts:

	app/controllers/districts_controller.rb
	app/models/district.rb
	app/views/districts/lookup.rjs
Remove vendored rails
remove depricated session_key in favor key
Center the map on the whole district, rather than one of its polygons
Conflicts:

	app/controllers/districts_controller.rb
Move lookup js out of the view and into application.js
+ fixing missing end in districts_controller.rb
Conflicts:

	app/views/districts/lookup.html.erb
	public/javascripts/application.js