mtree: Update mtree flags in README file

- Add -b (suppress blank lines before directories).
- The equivalent of `-i` in fmtree is `-j` in mtree (nmtree) (indent the
output 4 spaces).
- Add `-F freebsd9` compatibility flavor (print the closing `..` at the
end).

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/912

etc: remove leftover leading empty comments, blank lines

Remove leftover empty leading comments/blank lines that had been
spacers between $FreeBSD$ and the following content in config files
in src/etc.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D41548

Remove $FreeBSD$: one-line bare tag

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

Fix a small typo nit

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Removed "tail +5" from the command used to sanity check changes to
mtree files -- the 5-line header is no longer printed when mtree(8)
is run with -n (as of mtree/create.c,v 1.34).

Approved by: re (kensmith)

Sigh, this README is not a shell script.

Remind developers to update hier(7) if they make changes to these files.

Fix a small typo

Add missing -p /tmp/MTREE to mtree command in README so that it
will actually work now.

Remove tabs and once again sort the *.dist files.

$Id$ -> $FreeBSD$

Fix script in README to actually work, empty lines produce as
much a diff as lines with the wrong stuff on it.

Add references in mtree data files to the README.

An explination of how to keep these files in good working order.

Reviewed by: bde