changegroup: add "vfs" argument to "writebundle()" for relative access via vfs Before this patch, filename specified to "changegroup.writebundle()" should be absolute one. In some cases, they should be relative to repository root, store and so on (backup before strip, for example). This patch adds "vfs" argument to "writebundle()", and makes "writebundle()" open (and unlink) "filename" via vfs for relative access, if both filename and vfs are specified.

localrepo: make "undofiles()" return list of tuples "(vfs, relative filename)" Before this patch, "localrepository.undofiles()" returns list of absolute filename of undo files. This patch makes it return list of tuples "(vfs, relative filename)" to access undo files via vfs. This patch also changes "repair.strip()", which is the only user of "localrepository.undofiles()".