Tiles@home/nextgen

The next generation Tiles@home client will try to do some things better than the "old" one. Some of those cannot easily be backported, so this may be a complete replacement for the old client in the future.

Currently the project is used as a testbed for new things in tiles@home. It is nowhere near production ready.

One of those was AppConfig, another one is the splitting of z12 data into smaller stuff for less resource intensive rendering of densely mapped tile areas.