Fix https://github.com/junegunn/fzf.vim/issues/1116

Fix the regular expression to capture the command containing asterisk.

- Update to latest tcell which has 24 bit Windows support
- light renderer under Windows defaults to Dark256, if possible
- Respect TCELL_TRUECOLOR
- Remove tcell 1.3 references

Use 2-space horizontal padding so that the preview content is aligned
with the candidate list when the position of the preview window is `up`
or `down`.

Fix #2138
Fix #2029

Related: https://github.com/junegunn/fzf.vim/issues/1092

This is to allow line numbers in a ctags output (e.g. 123;")

Fix #1618

Close #1057
Close #2120

  # Initial scroll offset is set to the line number of each line of
  # git grep output *minus* 5 lines
  git grep --line-number '' |
    fzf --delimiter : --preview 'nl {1}' --preview-window +{2}-5

Preserve current directory in case current directory is changed by others
after the call of s:open

Co-authored-by: Junegunn Choi <junegunn.c@gmail.com>

Close #2086

Nix can be installed on (almost) any Linux distro and on macOS.

See https://nixos.org/nix/ for more information.

Close #2081

Fix #2093

And we'll phase out height specification with `~` prefix.

Fix #2010
Fix #1638

Fix #2088

Vim 8.1.2371
https://github.com/vim/vim/commit/05ad5ff0ab34ed9a5296dedd420ca81698b8ce22

Nvim 0.4.0
https://github.com/neovim/neovim/commit/9a1675b065394734ddaef91a314896028e2b1d46

Fix #2087

If a user has the Powershell Community Extensions installed, it comes
with another command Expand-Archive that doesn't have a DestinationPath
argument, causing an error.

* Use --line-range instead of head in bat example

* README: extend preview section

When called with popup options, do not move to temp window.

The action takes place in the alternate screen so the offsets should
still be correct.

* No need to restore &wfw and &wfh when using popup window

Co-authored-by: lacygoill <lacygoill@lacygoill.me>
Co-authored-by: Junegunn Choi <junegunn.c@gmail.com>

Fix #2038 

s///r is only available since perl 5.14. The Perl oneliner
was changed to work with older Perls, possibly even with 5.000.

Fix #2001