Fix a typo in reference/gosu.rb

milliseconsd ->
milliseconds
          ^^
Merge pull request #204 from myokoym/fix-a-typo-in-reference

Fix a typo in reference/gosu.rb
Add init callback to zen
Merge pull request #209 from myokoym/add-init-callback-to-zen

Add init callback to zen
Workaround for draw before update on Windows

See #208 on github