Based on 'FbmWarp' by hanker and ported by JiPi.
Like a few shaders, this shader did not work after conversion. I have found a "workaround" here, but I have to investigate the cause further. Here is an interesting use of the "Fractional Brownian Motion", which is only hinted at in the original. In this example gif the shader "Flight through a nebula V3" was used.
