Merged James Rowe's arch-shouldn't-create-userwide-config-file patch.

Merged James Rowe's arch-shouldn't-create-userwide-config-file patch.

From his email to the be-devel list:

From: James Rowe <jnrowe@ukfsn.org>
Date: Tue, 3 May 2009 11:44:41 +0000
Subject: [PATCH] Don't create config file unless we're using arch.

Hi,

  I find the current behaviour of creating a config file simply to set
a default for a revision control system I'm never going to use to be
a little annoying, the attached patch changes this behaviour to only
set the default in the config file if you're actually using arch.

Thanks,

James