nativelite-vterm 0.5.5

Added

• cargo bench --bench feed_throughput: a standard-library-only benchmark
  of Term::feed, in benches/, over generated streams: plain ASCII, agent
  output, SGR-heavy text, cursor redraws, UTF-8, a mix of those, and the agent
  stream into Term::with_history. Median MiB/s of five runs, about 4 s in
  release. benches/README.md says what each number means, has this
  release's results, and names where every performance figure in this
  changelog came from. The 0.5.4 entry below now says which of its figures
  came from a harness outside this repo, beside the bench's own number.

Fixed

• A restored terminal keeps its scrollback capacity. Term::restore built
  a terminal with no history, so one made by Term::with_history came back
  with history_capacity() 0 and never recorded a scrolled-off line again.
  Checkpoint format 4 carries the capacity — the line count and the byte cap
  (set_history_bytes) — and a restored terminal starts with an empty history
  that fills as it scrolls and holds through a resize. The lines themselves are
  still not in a checkpoint: they belong to whoever keeps the checkpoints.
  Older checkpoints restore as before, with no capacity. A restore also leaves
  runs of the blank cell unwritten, as they were, so a restored screen's blank
  rows do not scroll into the history as lines the original never recorded.