Remove $FreeBSD$: one-line bare tag

Remove /^\s*\$FreeBSD\$$\n/

Fix spelling error.

Reported by: junovitch

Add libnetbsd, a thin compatibility layer intended to allow a limited
set of NetBSD software to compile as part of the FreeBSD build with
little or no modifiction. It is built as a static library and not
installed for general use. Likewise, its header files are not
installed.

Sponsored by: DARPA, AFRL