Squashed 'Custom-Metaboxes-and-Fields-for-WordPress/' content from commit cdb1c46

git-subtree-dir: Custom-Metaboxes-and-Fields-for-WordPress
git-subtree-split: cdb1c46982039578f1c8a55696ea72d3fe291802
Merge commit '152be4ed5151ed1ea79474ac751c34d8a7e9b256' as 'Custom-Metaboxes-and-Fields-for-WordPress'
Experiments in subtree subproject management