Example:
  echo -en '  \e[48;5;232mhello\e[48;5;147m  ' | fzf --ansi --with-nth 1

Close #4422

Options:
  --footer=STR             String to print as footer
  --footer-border[=STYLE]  Draw border around the footer section
                           [rounded|sharp|bold|block|thinblock|double|horizontal|vertical|
                            top|bottom|left|right|line|none] (default: line)
  --footer-label=LABEL     Label to print on the footer border
  --footer-label-pos=COL   Position of the footer label
                           [POSITIVE_INTEGER: columns from left|
                            NEGATIVE_INTEGER: columns from right][:bottom]
                           (default: 0 or center)

The default border type for footer is 'line', which draws a single
separator between the footer and the list. It changes its position
depending on `--layout`, so you don't have to manually switch between
'top' and 'bottom'

The 'line' style is now supported by other border types as well.
`--list-border` is the only exception.

  # The first line of the second chunk would prematurely wrap
  printf '%0500s\n\n%0500s' 0 0 | fzf --wrap --read0

Close #4282

This option can be used to replace a sed or awk in the post-processing step.

  ps -ef | fzf --multi --header-lines 1 | awk '{print $2}'
  ps -ef | fzf --multi --header-lines 1 --accept-nth 2

This may not be a very "Unix-y" thing to do, so I've always felt that fzf
shouldn't have such an option, but I've finally changed my mind because:

* fzf can be configured with a custom delimiter that is a fixed string
  or a regular expression.
* In such cases, you'd need to repeat the delimiter again in the
  post-processing step.
* Also, tools like awk or sed may interpret a regular expression
  differently, causing mismatches.

You can still use sed, cut, or awk if you prefer.

Close #3987
Close #1323

Fix #4083