Interrupt handling during execute action was not serialized and often
caused crash, failed to restore the terminal state.

* _fzf_complete is the helper function for custom completion
    * _fzf_complete FZF_OPTS ARGS
    * Reads the output of the source command instead of the command string
    * In zsh, you can use pipe to feed the data into the function, but
      it's not possible in bash as by doing so COMPREPLY is set from the
      subshell and thus nullified
* Change the naming convention for consistency:
    * _fzf_complete_COMMAND

e.g.

  # pass completion suggested by @d4ndo (#362)
  _fzf_complete_pass() {
    _fzf_complete '+m' "$@" < <(
      local pwdir=${PASSWORD_STORE_DIR-~/.password-store/}
      local stringsize="${#pwdir}"
      find "$pwdir" -name "*.gpg" -print |
          cut -c "$((stringsize + 1))"-  |
          sed -e 's/\(.*\)\.gpg/\1/'
    )
  }

  # Only in bash
  complete -F _fzf_complete_pass -o default -o bashdefault pass

While in bash you can externally register custom completion functions
using `complete` command, it was not possible to do so in zsh without
changing completion.zsh as the name of the supported commands are
hard-coded within the code (See #362). With this commit, fzf-completion
of zsh will first look if `_fzf_COMMAND_completion` exists and calls the
function, so one can externally define completion functions for specific
commands.

This commit also tries to make the interface of (yet undocumented)
_fzf_list_completion helper function consistent across bash and zsh.

So the following code works both on bash and zsh.

    _fzf_pass_completion() {
      local pwdir=${PASSWORD_STORE_DIR-~/.password-store/}
      local stringsize="${#pwdir}"
      let "stringsize+=1"
      _fzf_list_completion '+m' "$@" << "EOF"
        find "$pwdir" -name "*.gpg" -print | cut -c "$stringsize"- | sed -e 's/\(.*\)\.gpg/\1/'
    EOF
    }

    # Only on bash
    complete -F _fzf_pass_completion -o default -o bashdefault pass

Note that the suggested convention and the interface are not yet final
and subject to change.

/cc @d4ndo

This change improves sort ordering for aligned tabular input.
Given the following input:

    apple   juice   100
    apple   pie     200

fzf --nth=2 will now prefer the one with pie. Before this change fzf
compared "juice   " and "pie     ", both of which have the same length.

Remove dependency on zsh/pcre module

Fixes #363.

[vim] handle SwapExists

The SwapExists dialog prevents multiple files from being opening if the
dialog occurs before all files are opened. Opening the files is more
important than showing the dialog, so choose "readonly" automatically
and continue opening files.

Related: https://github.com/junegunn/fzf.vim/issues/16

Close #354

This reverts commit 987799f8.

This reverts commit d2f3604c.

Instead of building a separate statically-linked binary, build
partially-static binary that only contains ncurses to avoid
compatibility issues in libc.

Related: #345

and allow using --header and --header-lines at the same time.

Close #346.

A la grep. Close #345

Close #338

Fixes Helptags! command from fzf.vim

Fix CTRL-T on fish to work asynchronously