gui_toolkit 0.56.1

Added

• flate.deflate_runs: compression at a high rate for what repeats in known ways, such as the rows of a picture: runs and matches a row above, in one block of the fixed Huffman codes.

Fixed

• A screenshot of a real window took two seconds and froze it: the wake asked for its next frame was consumed by the frame already starting, so the window slept until its next timer (about 1.2 s); reading a translucent window's fp16 target back ran pow on every channel (now a table); the PNG was encoded on the UI thread (now flate.deflate_runs, made for rate, on a thread of its own). A timeline keeps its pictures in memory and compresses, compares and writes them when it ends. An offscreen window keeps its wakes, so the end-to-end run never saw the first one.