Fix an irritating error message
Breath meter flashes when drowning
Merge remote-tracking branch 'rainChu/drowning-gauge'
Removed a workaround from Renderer, some cleanup
Refactored Ogre initialisation into a component
Delete README_Mac.md

Use updated manual from wiki: https://wiki.openmw.org/index.php?title=Development_Environment_Setup#Mac_OS_X