* vc-p4.el (vc-p4-diff): Support lists of files.
Perform only a
single request to the server in the simplest case (diff edited
file to synced version).
* p4-lowlevel.el (p4-lowlevel-command-into-buffer): Don't reorder
info and text lines.
(p4-lowlevel-diff): Support lists of files as well as a single file.