Avoid storing options instance variable in BlockBody.

There is no need to pass parse options to the BlockBody initializer, since
it does all the parsing in the parse method, unlike tags which parse the
tag markup in the initializer.

lib/liquid/document.rb

@@ -1,17 +1,23 @@
 module Liquid
   class Document < BlockBody
-    def parse(tokens)
+    def self.parse(tokens, options)
+      doc = new
+      doc.parse(tokens, options)
+      doc
+    end
+
+    def parse(tokens, options)
       super do |end_tag_name, end_tag_params|
-        unknown_tag(end_tag_name) if end_tag_name
+        unknown_tag(end_tag_name, options) if end_tag_name
       end
     end
 
-    def unknown_tag(tag)
+    def unknown_tag(tag, options)
       case tag
       when 'else'.freeze, 'end'.freeze
-        raise SyntaxError.new(@options[:locale].t("errors.syntax.unexpected_outer_tag".freeze, :tag => tag))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_outer_tag".freeze, :tag => tag))
       else
-        raise SyntaxError.new(@options[:locale].t("errors.syntax.unknown_tag".freeze, :tag => tag))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag".freeze, :tag => tag))
       end
     end
   end