Squashed 'tools/libs/leveldb/' content from commit 269fc6c

git-subtree-dir: tools/libs/leveldb
git-subtree-split: 269fc6ca9416129248db5ca57050cd5d39d177c8
Merge commit 'c103119dbaf876a472d04e0677d00dbfd269de55' as 'tools/libs/leveldb'