I was too quick to release 0.16.9, this commit makes --ansi processing
even faster.

When --with-nth is used, fzf used to preprocess each line and store the
result as rune array, which was wasteful if the line only contains ascii
characters.

- Fix incorrect display of the last line when more than a line is
  wrapped above
- Avoid unnecessary flickering of the window

This change gives 5x speed improvement

Related: https://gist.github.com/junegunn/4963bab6ace453f7f529d2d0e01b1d85

Close #974

Fix https://github.com/junegunn/fzf.vim/issues/404

Thanks to @janlazo.

By not storing item index twice, we can cut down the size of Result
struct and now it makes more sense to store and pass Results by values.
Benchmarks show no degradation of performance by additional pointer
indirection for looking up index.

- Remove multiple mutex locks in partial cache lookup
- Simplify return values

Close #966

Related: #960 (relative filepaths)

Related #960, #552

With zero result.

Related: https://github.com/junegunn/fzf.vim/issues/22#issuecomment-311869805

This also modifies <C-t> behaviour.
The longest file path in the input is used as root directory for `find`
command. The remainder of the input is passed to fzf's --query as a
initial search parameters.

Fix found by @amosbird at https://github.com/junegunn/fzf/issues/953#issuecomment-310309055

closes #440

See #944

fzf should immediately continue consuming the buffer after discarding
bracketed paste mode sequence.

Close #951

If "." is given as the argument to begin <C-t> completion, the leading
"." is not correctly removed. In general, if user selects a fzf
completion, the current token should be "consumed".

Close #943

See https://github.com/junegunn/fzf/pull/933#discussion_r120011934

Close https://github.com/junegunn/fzf.vim/pull/386

Also change the example binding for `unix-word-rubout` to *ctrl-w* instead of *ctrl-u*

Close #935

- Update install script to download Windows binary if $TERM == cygwin
- Unset TERM if $TERM == cygwin (#933)
- Always use cmd.exe instead of $SHELL when running commands