Squashed 'src/leveldb/' content from commit a02ddf9

git-subtree-dir: src/leveldb
git-subtree-split: a02ddf9b14d145e88185ee209ab8b01d8826663a
Merge commit 'cb1e39f0a35cc2b36fb748c26f69cd27e0ed5332' as 'src/leveldb'