added grid subdivision algorithm for heightmaps.

Signed-off-by: Felix Dietrich <felix.dietrich@tum.de>
fixed rescaling issue, now all subdivisions are scaled correctly.

Signed-off-by: Felix Dietrich <felix.dietrich@tum.de>
added layer plotter.
added .txt files to gitignore.

Signed-off-by: Felix Dietrich <felix.dietrich@tum.de>
more on population density.
added subdivision of population density maps.

Signed-off-by: Felix Dietrich <felix.dietrich@tum.de>