Update version

Set sprite to null in sprite animation clip if sprite asset is remove…

…d without checking if asset.resource is the same as the sprite because the asset.resource might already be null

Merge branch 'master' of github.com:playcanvas/engine

Pass correct value in showFrame in sprite animation clip

FIX: correctly set material when enabling/disable mask property

Reinstate dt clamping and expose ability to set upper bound. (playcan…

…vas#1128)

Default opacity channel should be A (playcanvas#1117)

* default opacity channel = 'a'

Fix iOS after recent shader chunk changes

Update README.md

- Use particleDistance values in vbToSort array instead of indices, a…

…rray lookups in sort function are expensive (playcanvas#1072)

- Use TypedArray.set instead of manually copying elements into vbOld - TypedArray.set does an optimised copy
- Unroll for loop in sorting code, saving an inner loop and a few multiplies per vertex