First working flycam version with interesting HUD effects
missing files
merge with master
Make input flow a bit more generic, allow free/normal cam switch at any
time
Move sound listener with freecam
Add hotkey to howto.md
fix mouse input for flycam
Merge remote-tracking branch 'origin/master' into flycam
Render starfield around current camera
Merge remote-tracking branch 'origin/master' into flycam

Conflicts:
	src/gamestate/gameplay/gameplay.cpp
	src/gamestate/gameplay/gameplayscene.cpp
	src/gamestate/gameplay/input/gameplaynormalinput.cpp
	src/gamestate/gameplay/input/gameplaynormalinput.h
	src/gamestate/gameplay/running/gameplayrunning.cpp
fix "digital" mouse input behaviour by removing all limits/normalizations in freecam
remove unused includes
Move setInertia to InertiaFollower
Switch InertiaFollower inertia range
Fix assertion
Merge remote-tracking branch 'origin/master' into flycam

Conflicts:
	src/gamestate/gameplay/input/gameplaynormalinput.cpp
remove include windows.h
Merge pull request #488 from voxelinc/flycam

Flycam
Merge branch 'master' of github.com:voxelinc/voxellancer into handle_improvements
Merge branch 'handle_improvements' of github.com:voxelinc/voxellancer into worldtreenoderef