* Redesigned alpha blending and paint drying algorithms. Now it gives much better results when using low brush alpha or when surface has initial color set. * Fix: "Slow" dissolve/dry was scaled incorrect when using substeps. Also adjusted time to better match non-"slow" setting. * Fixed possible issues when using image textured brush. * Fix: particle brush panel was no longer visible since last commit. * Adjusted default surface values. * Some more code cleanup.