Changed a little part in Drowned Veins — Northern Journey Steam update #824403

There was a place in Drowned Veins that seemes to have confused some people. I have blocked away the confusing part, and added two more Permanent health flask into that level. The volume control in main menu settings has gotten a range of 0..1, instead of 0.5..1. This means the music can be fully disabled - but, it is not recommended, because a lot of ambient noise is also lost. When hiding the HUD for screenshot purposes (or just pressed the key by mistake), the HUD will automatically re-appear after 5 seconds. I have seen some people not getting important onscreen messages because those are also hidden. Added some collisionboxes in the tunnell under the river in Greenslit. The player could get stuck, and had to jump to walk some stairsteps.