Improvements: Speed & Accuracy

Over the last few days I've improved the response time of most ShipWatcher functions. It should be loading a lot faster now. If you notice delays, please let me know.

One other thing I've improved is estimating where a ship is. Some ships don't broadcast their position. They only tell us where they came from and where they're headed. I've given ShipWatcher a bit more intelligence so that it can guess the latitude and longitude of a ship, even if it doesn't know its exact position. It does this by looking at journeys from other ships that may have travelled a similar route in the past.

If any of the information seems incorrect, please let me know. I can't watch every single ship all the time, so sometimes I don't see when the data is wrong.