0.50.0

- Search performance optimization. You can observe 50%+ improvement in some scenarios.
  ```
  $ rg --line-number --no-heading --smart-case . > $DATA

  $ wc < $DATA
   5520118 26862362 897487793

  $ hyperfine -w 1 -L bin fzf-0.49.0,fzf-7ce6452,fzf-a5447b8,fzf '{bin} --filter "///" < $DATA | head -30'
  Summary
    fzf --filter "///" < $DATA | head -30 ran
      1.16 ± 0.03 times faster than fzf-a5447b8 --filter "///" < $DATA | head -30
      1.23 ± 0.03 times faster than fzf-7ce6452 --filter "///" < $DATA | head -30
      1.52 ± 0.03 times faster than fzf-0.49.0 --filter "///" < $DATA | head -30
  ```
- Added `jump` and `jump-cancel` events that are triggered when leaving `jump` mode
  ```sh
  # Default behavior
  fzf --bind space:jump

  # Same as jump-accept action
  fzf --bind space:jump,jump:accept

  # Accept on jump, abort on cancel
  fzf --bind space:jump,jump:accept,jump-cancel:abort

  # Change header on jump-cancel
  fzf --bind 'space:change-header(Type jump label)+jump,jump-cancel:change-header:Jump cancelled'
  ```
- Added a new environment variable `$FZF_KEY` exported to the child processes. It's the name of the last key pressed.
  ```sh
  fzf --bind 'space:jump,jump:accept,jump-cancel:transform:[[ $FZF_KEY =~ ctrl-c ]] && echo abort'
  ```
- fzf can be built with profiling options. See [BUILD.md](BUILD.md) for more information.
- Bug fixes