New ChunkProvider implementation

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Fix another UE deadlock

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Use CHashMap in UE ElectricityConnections

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Ignore null keys/values in CHashMap.contains

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Implement more of ThreadedChunkProvider

Signed-off-by: Ross Allan <rallanpcl@gmail.com>