Expand collection laziness to data

middleman-core/lib/middleman-core/core_extensions/data.rb

@@ -14,11 +14,11 @@ module Middleman
 
       def initialize(app, config={}, &block)
         super
+
         @data_store = DataStore.new(app, DATA_FILE_MATCHER)
         app.config.define_setting :data_dir, 'data', 'The directory data files are stored in'
 
         app.add_to_instance(:data, &method(:data_store))
-        app.add_to_config_context(:data, &method(:data_store))
 
         start_watching(app.config[:data_dir])
       end