removing split core code
Squashed 'lib/core/' content from commit 550124e

git-subtree-dir: lib/core
git-subtree-split: 550124ea14eb1f594ec4f979819b618d5bd087d1
Merge commit '4b6aad8016b0827ce5f8fc410fbff1f3d05a5ef0' as 'lib/core'