fix: model component set asset to null on change type to non asset
Fixed particle system cloning.
Merge pull request #78 from guycalledfrank/particle-system-clone-fix

Particle system clone fix
Added crossOrigin property to TextureResourceHandler
Set to "anonymous" to enable cross origin texture loading.
Correctly initialise emitterScale
Correct date in shaderchunk generator
[RELEASE] v0.159.2
[VERSION] v0.160.0-dev
Changed light.falloffMode description
Added filter for shadowResolution to only show up when castShadows is true
Added CURVE_CATMULL and CURVE_CARDINAL to pc.Curve()
Merge branch 'master' of github.com:playcanvas/engine
[FIX] pc.Curve with no keys
[FIX] Emissive maps work again.
[RELEASE] v0.159.3
[VERSION] v0.160.0-dev
[FIX] Catmull curves now respond correctly to points with non-uniform time between them.
Merge branch 'master' of github.com:playcanvas/engine
[FIX] particlesystem component reset function now works for one shots if lifetime is less than reset interval.
Added clamping to curves. Not used yet