gui_toolkit 0.8.1

Added

• Status bars and frame statistics (ui/status.odin): status_bar(id) (a bar along the bottom of a window, theme
  tags "bar", text a little smaller), status_fill(id) (the flexible part of the bar: takes the room left, clips its
  items), status_item(id, tone, mono, clickable, width), status_separator().
• Frame_History: a ring of History_Samples (up to HISTORY_SERIES = 8 stacked values, a time, an app tag):
  history_init / history_destroy / history_resize (keeps the newest) / history_clear / history_push /
  history_at / history_last / history_find_tag (complete a sample later: GPU times arrive a few frames late) /
  sample_total; history_stats(h, since_ms, budget) (n, mean, min, max, p50, p95, p99, over budget, per-series mean
  and max, span) and history_rate(h, now_ms, window_ms) (samples per second).
• frame_graph(id, &history, Frame_Graph_Opts): one stacked bar per sample, newest at the right; per-series colors,
  series (draw more series than the history counts, e.g. a GPU time over the CPU phases), bars, a dashed budget
  line, scale / max_scale (the top fits most bars; a rare spike is cut and marked instead of flattening the rest),
  warn / bad cap marks, highlight. The result is the box's signal plus the history index of the bar under the
  pointer. graph_scale gives the top it uses. Nothing asks for frames.
• stat_row(id, label, value, width, mono, swatch_color, tone), stat_heading, swatch: rows of detail panels and
  graph legends.
• popover(id, anchor, width, side, align_right): a floating panel above or below a widget (the other side when it
  does not fit, clamped to the window), open as long as the app builds it; popover_rect(id) for input the app routes
  itself.
• render.set_gpu_timing(r, on): the GPU time of each frame_submit measured at run time, without
  -define:GPU_TIMING (timestamp queries in a ring, read back later: the CPU never waits); gpu_timing_enabled,
  gpu_next_frame and gpu_result (the time and the index of the submit it measured, to attribute it to its frame).
• render.texture_memory(r): GPU memory of the renderer's textures by kind (glyph atlases, images with their mips,
  layer targets).
• examples/fidget: its status bar uses them (build and draw time per frame, stacked, with a tooltip per frame).