If you have selected some files, you intend to work on them. Also, this prompt
expects <kbd>c</kbd> / <kbd>s</kbd> which should cancel the next prompt in the
delete workflow. Rest of the three workflows are non-fatal.

Benefits of removing this option:
- code reduction
- one less step in the relevant workflows (more than one prompt feels dragged)

This prompt shows in the following workflows:
- delete: users have explicitly requested to prefer sel over current
- batch rename: key <kbd>^R</kbd> renames a single file
- archive: in most of the cases the user would want to archive the selection
- create sym/hard link: not a frequently used workflow (in general)

Code named after Freddie Mercury: https://en.wikipedia.org/wiki/Freddie_Mercury

If an input stream is available, prioritize that over sessions. find/grep
syntax can be very complex and can be scripted. On the contrary, sessions
can be loaded at runtime and the persistent session can be "restored".

An interesting use case is the listing is done in picker mode from a script
and the user expects to "pick" some entries among the listed search results.

Another important change is - if the user tries to load the "last session"
explicitly by name instead of using the session option _restore_, we should
not overwrite the "last session" ("@") before loading the it.

Without this, there is a conflict with using the `-u` option (use selection).
After copying selected files, the selection is intact and if the user issues
a deletion next, the source files (meant for copying) are deleted.

This is a trial patch to fix the typos

Signed-off-by: SZ Lin (林上智) <szlin@debian.org>

* Add -a option to generate a temporary NNN_FIFO

* Add documentation for -a option

* plugins/README.md: promote the use of -a

This obsoletes the global FIFO unlink trick, so I remove mentions of it.
@jarun update:

Polish -a

* Allow launching plugins with Alt + plugin's key

* Fix Alt key in filter/prompts modes

* Fix handling Alt key in nextsel()

In filter mode: run the associated plugin.
In prompt mode: just throw out the Alt+key input.
In nextsel(): differentiate Alt+key and Esc

* Add an option to print hovered files to a FIFO

This adds an env variable, `NNN_FIFO`, that can be set to a path that
`nnn` will open/create as a FIFO, and where every hovered file's path is
printed. This allows creating external perview/quick open plugins, ...

It can be compiled out with the make variable `O_NOFIFO`.

* Check filename ptr instead of full path (for FIFO)

* Add documentation to use NNN_FIFO in plugins

* Fix path sent to FIFO in empty dirs