share: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line nroff pattern

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

Explicitly declare to not print the current date

Found with heirloom-doctools which uses the original AT&T macros

Reincorporate documentation lost with update to nvi 2.1.3