add leveldb
add leveldb

EvilMcJerkface/atlasdb,palantir/atlasdb,palantir/atlasdb,j-baker/atlasdb,EvilMcJerkface/atlasdb,andy2palantir/atlasdb,andy2palantir/atlasdb,j-baker/atlasdb,EvilMcJerkface/atlasdb,j-baker/atlasdb,sh4nth/atlasdb-1,sh4nth/atlasdb-1,palantir/atlasdb