mruby/mruby — pull request #523 by skandhas (2012-11-01 08:51:56+00:00)
Title: fix when mruby parse embedded rd document, mruby throw a syntax error.

Example：
```ruby
=begin
=end
=end

=begin
= end
=end

=begin
= eeeeeend
=end

=begin
g_game = RavenGame.new

1000.times do |i|
g_game.update
end
=end

p "Test"

```

These embedded rd documents could make mruby throw syntax error.