Initial commit
Add 'core/' from commit '2c8662cf9ea636b18f7d60780b820bf4dbc307ba'

git-subtree-dir: core
git-subtree-mainline: 066c9c94878993739063270e3174a4591161e468
git-subtree-split: 2c8662cf9ea636b18f7d60780b820bf4dbc307ba