pfSense

Always use require_once

The usage of require() and require_once() throughout the system is
inconsistent, and "bugs" come up now and then when the order of
"requires" is a bit different and some require() happens after the
include file is already included/required....

Delete Id comment lines from etc files

A bit more crud cleaned out
Note: lots of the /etc files have old style copyright stuff or no
copyright stuff.

Move main pfSense content to src/