update to v0.7 of dfm

* dotfiles repository can now be outside of home directory, using $DFM_REPO
* add help subcommand and refactor help handling
* make 'help' the default subcommand (seth--)
* better parsing of arguments to preserve all arguments passed through to git subcommands
remove mention of personal dotfiles, they are in another repo
Merge remote-tracking branch 'justone/master'

Upgrade to dfm 0.7.

Conflicts:
	README.md
Enable automatic pruning in git fetch.

I hate having stale remote tracking branches lying around. Luckily Git
1.8.5 introduced an option for that.
Fix listing of changes in git-branch-pull.

This code was using $headHash..$remoteHash where it should have been
using $mergeBase..$remoteHash. We only want to see the incoming
changes, not the difference between HEAD and upstream.
Introduce a --fetch-only option to git-branch-pull.

Now that I have the handy summary of incoming changes in git-branch-
pul, I sometimes find my self wanting to run it to get a preview of
upstream changes before actually deciding to pull them into my branch.
Hence, --fetch-only.
Introduce 'git bfetch' as an alias for 'git bpull --fetch-only'.
Copy git-branch-pull's change summary to git-branch-push.

Doing a push is the most significant operation one does in Git, so
it's nice to see a summary of what you actually chose to push.
Add a --prompt option to git-branch-push.

Now that I have fancy push change summaries, I find myself wanting to
preview the set of changes to push, without necessarily going ahead
with the push. Hence, the --prompt option.
Introduce 'git bpush' as an alias for 'git bpush --prompt'.
Simpler usage handling in scripts.

We always want to exit after calling usage(), so we should just get
usage to do it for us.
Detect multiple flags in git-branch scripts.

Neither of these scripts supports multiple flag arguments, so we
should give a friendlier error if that happens. Previously, the script
would try to interpret the second flag as a remote branch name and
error out, which isn't a stellar user experience.
Switch to single quoting where appropriate in git-branch scripts.

I've flip-flopped on this before, but I've decided to prefer single
quoting strings when substitution isn't required. It just seems
cleaner.
Realphabetize .gitconfig.

Yes, I really am that picky.