October maintenance update — fault - milestone one Steam update #379819

Hello again! It's the usual maintenance update. (Re-released just now to remove something unfinished that sneaked in.) Changes from the last update are below. As always, the complete changelog is on the forums. The artbook can now be opened in-game via the gallery. The engine doesn't recompile itself on first run for fun anymore. This was why 100 files were always redownloaded when verifying integrity. Fixed the skip after choice preferences being reversed. Fixed a few misnamed tracks in the music room. Achievement progress isn't cached in save data anymore.