Patches sent as attachments aren't well-formatted for 'pwc git-am' or 'git pw apply'

[nwnk]

Example: http://patchwork.freedesktop.org/patch/68368/mbox/

Feeding that into git pw apply for xserver at commit f3593918a0507cc080875788b2776ebe4f57c694 will create a commit whose topic is the containing Subject line, and whose body is a concatation of the containing message body and the attachment. It's possible to recover from this with clever use of git commit --amend but it'd be nice to get right up front.