Added a new feature to et-gtk: quick image saving. The time of program launch is stored, and pressing 's' saves an image with this timestamp and a sequence number in the filename. Uses the #Haskell 'xdg-userdirs' (to find "~/Pictures" regardless of language) and 'time' packages (to get the time and format it).
Eventually the PNG files will contain metadata (formula, coordinates, etc) that can be reloaded into the et GTK GUI, and I want to add a batch mode to the CLI renderer so I can point it at a bunch of such PNGS with options like "re-render all of these at higher resolution".
Even later I want to add an 'r' shortcut to add to a render queue, so I don't need to launch the CLI renderer manually.
I re-enabled "ignore isolated glitches" for non-progressive rendering (as used in the CLI renderer, but not the GTK GUI). This speeds up high resolution perturbation rendering at the cost of inaccuracy (hopefully invisible after downscaling).
Theoretical worst case is 1/4 of pixels being wrong, but that is highly unlikely in practice.