Changed YAML delimiter matcher so as to not chew up 2nd level markdown headers

lib/jekyll/convertible.rb

@@ -13,7 +13,7 @@ module Jekyll
     def read_yaml(base, name)
       self.content = File.read(File.join(base, name))
       
-      if self.content =~ /^(---.*\n.*?)\n---.*\n/m
+      if self.content =~ /^(---\s*\n.*?)\n---\s*\n/m
         self.content = self.content[($1.size + 5)..-1]
         
         self.data = YAML.load($1)