Squashed 'pi4j/' content from commit f570ac1

git-subtree-dir: pi4j
git-subtree-split: f570ac160f8f40431585d80496438c8638e4f76a
Merge commit 'd501dae06039c1f111a0a0d5f3c3e0523d3d5cca' as 'pi4j'
Initial Commit