Both in light and detail modes we show more characters than in status bar.

This reverts commit 681b22d5c7.

The statvfs man page:
http://man7.org/linux/man-pages/man3/statvfs.3.html

says clearly:

fsblkcnt_t     f_blocks;   /* Size of fs in f_frsize units */

I missed this earlier.

Replaces the following environment variables:
- NNN_USE_EDITOR
- NNN_IDLE_TIMEOUT

This reverts commit 527e995f1f.

* Quit with an error code

* Use `Q` as "quit with err"

* Remove extra var and simplify conditions

* Revert combining conditions

* Fix formatting

* Format help with as much tabs as possible

* Catch NULL from malloc()

* Tidy up errors

* Make indentaion look pretty in git