get_maintainer.pl: Adjust to Xen workflow
Based on feedback from reviewers:
* Disable git fallback by default: it has a tendency to mail
anyone who did a single oneline change and should not be
necessary for a project of Xen's size.
* Disable rolestats: Makes cut-and-paste from the output into the
commit message easy.
* Drop "THE REST" fallback: Don't spam Keir *too* much.
Signed-off-by: Don Slutz <dslutz@verizon.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ijc -- expanded the changelog]