Add UTF-8 encoding where we read in YAML so it reads in UTF-8 characters properly. Fixes #836.

lib/jekyll/configuration.rb

@@ -1,3 +1,5 @@
+# encoding: UTF-8
+
 module Jekyll
   class Configuration < Hash
 

lib/jekyll/convertible.rb

@@ -1,3 +1,5 @@
+# encoding: UTF-8
+
 require 'set'
 
 # Convertible provides methods for converting a pagelike item