lsof-4.97.0

[decof/du/tru64] Remove support because the os is no longer updated for more than 10 years

[openstep/nextstep] Remove support because the os is no longer updated for more than 20 years

Add experimental build system based on Autotools (#270)

Fixed LTsock testing on darwin (#272)

Remove NEW and OLD folders (#6)

Fix FreeBSD testcases (#271)

Rewrite documentation and publish at https://lsof.readthedocs.io/