1. The debug file is located at /tmp/nnn_debug.
2. Debug mode is completely disabled by default. The debug binary `nnndbg` can
be built by running `make debug`.

^Q would quit even from filter mode

On Mac and error is thrown if the regex expression to regcomp() is empty.

Please refer to comments at:
c42df81ae5

1. Open directories in filter mode
2. Fix arrow keys not working after filter selection (due to invalid cur entry)
3. Support `Insert` key to clear filter prompt
4. Update documentation

Reasons:

gnome-search-tool is much more powerful than other tools in its category. It
supports numerous search parameters like size, modification date and supports
text search.

Limit all xstrlcpy() calls by dest length.
Escape filenames in system(3) calls.