Revert "Fix z-index bug using CSS filter blur on translated element"

This reverts commit c038508d6d1ae265849dab7db5c3617e84e9efd6.
Revert "tidy up"

This reverts commit d565d1fa53ec1a9450b86d42e59a57ac9389bc58.
Revert "Revert last commit"

This reverts commit 25baad19255e09fef65f003875046c8bef01f607.
Add dual touch/mouse support, plus other bug fixes