sources: Pass any current mode to `_populateMetadata` when finding pages. Page sources like the `prose` source may need to open an existing page's file to read stuff from it. This won't work if the metadata is populated as part of finding a path to create a page (like when running `chef prepare`). We pass the mode to `_populateMetadata` so the underlying class now knows the current context in which it is called.

#!/bin/sh

CUR_DIR="$( cd "$( dirname "$0" )" && pwd )"
CHEF=${CUR_DIR}/../bin/chef
OUT_DIR=${CUR_DIR}/../piecrust/resources/messages
ROOT_DIR=${CUR_DIR}/messages

$CHEF --root=$ROOT_DIR bake -o $OUT_DIR
rm ${OUT_DIR}/index.html