Progress with 'custom_image' themes

After contacting kendy, I've been working on optimizing the crystal and industrial icon themes. They are generally much larger than the default theme, since the images are richer with more complex alpha transparencies. As a result, the potential for lossless optimization is not as good. The crystal set has now been finished and can be found here (1.32 to 1.15MB ~87%). The industrial set can be found here (1.83 to 1.35MB ~74%). Both themes would benefit from some hand tweaking, since at least some icons have been saved as 48bpp(!) so cannot be optimized with my method. However, I think it is a better use of my time to press on with the Icon Audit and tweaking the Default set.