New instructions for using git to track the DragonFly repo

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

    The repo has not changed but I've found a simpler set of instructions
    for checking out and managing it.   I did split a few steps to make
    them more obvious.  I am avoiding the use of git-clone because it hides
    too much of what goes on under the hood.

    (To start from scratch)

	# Create your new source dir
	#
	mkdir -p /usr/src
	cd /usr/src
	git init
	git remote add chlamydia git://chlamydia.fs.ei.tum.de/dragonfly.git
	git remote add crater git://crater.dragonflybsd.org/dragonfly.git

	# Initial fetch from chlamydia, then fetch from the (much slower) master
	# repo on crater.  Most of the data will thus already have been
	# downloaded from chlamydia, but your primary remote can be set to
	# the master repo on crater.
	#
	git fetch chlamydia
	git fetch crater

	# Create a local branch to track the master branch from crater
	# and do the initial checkout.  Use the same name to simplify
	# matters.
	#
	git branch master crater/master
	git checkout master

	# Updates your local branch from crater and adjusts your working
	# directory.  This keeps your sources up to date.
	#
	# Repeat as often as you like, manually.  If running from cron, no
	# more then once an hour please unless you are a mirror.  Mirrors
	# can pull every 5 minutes but should be sure to use the lockf
	# utility to avoid stacking pulls.
	#
	# Resyncing from crater should be fast once the initial repo has been
	# fetched from chlamydia.
	#
	git pull


    Tracking a release branch is very simple as well.  Create a local
    branch from the remote master, checkout, and pull to update.

	git branch DragonFly_RELEASE_2_0 crater/DragonFly_RELEASE_2_0
	git checkout DragonFly_RELEASE_2_0

	# And pull to update from crater and merge into your work directory
	# as desired.
	git pull

    Simply use git checkout to switch between branches.  More complex
    commands may be needed if you have local edits pending and you wish
    to switch between branches.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>