Here is another patch.
It changes the scaling of two patterns.
Most significantly the nature-reserve-pattern is changed in a manner
that the borders of the tiles fit to each other in all zoom levels. This
also reduces the size of a tile which is completely filled with
nature-reserve-pattern by over 50% and rendering speed is also a bit
higher than before (5-10%).
I hope you like the patch.
I plan to do more optimisations and therefore I ask for write access to