Fixing bug in multi-threaded reads in StreamIndexedIO.
Fixing bug in multi-threaded reads in StreamIndexedIO.

The problem was due to DirectoryNode instances created after expanding sub-indexes which had unsorted child nodes. That could cause sorting later by calls to findChild().

hradec/cortex,lento/cortex,lento/cortex,lento/cortex,appleseedhq/cortex,appleseedhq/cortex,hradec/cortex,goddardl/cortex,appleseedhq/cortex,goddardl/cortex,hradec/cortex,goddardl/cortex