Up version to r512

* Add monthly quests group
* Special quest that appear at special day are regarded as daily quests
* Fix translate (mixed english and japanese when change language to
japanese languages)
* Fix language isn't changed when change language
* Mute and capture button become bigger
* Use Segoe font instead of Meiryo
* Fix some other bugs
Merge remote-tracking branch 'origin/master' into gh-pages