Optimizations and map display bug fixes

[rupertbenbrook]

• Reducing the memory used when displaying map features, particularly when thousands are returned from the API
• Large speed up of map rendering by processing all the map features as a batch instead of individually
• Improving the map cache locking to avoid exceptions during map updates, especially large ones
• Removing map code that is no longer used
• Improving the performance of Settings loading when large number of map features are present
• Memory profiling of the map feature components to further reduce memory load