Create GeoTIFF file using GDAL instead of creating a PNG.

This allows for more flexibility. The GeoTIFF file contains the bounding box
and it contains the node count directly using more that the 8bit available
in PNGs.
Add tiff metadata.
Use real command line option parser.
Add configurable compression and overview building.
Simplified options handling and better progress output.
Add support for other projections.
Can give projections in libproj format in addition to EPSG code.
Add options to set bbox from command line.
Documentation for node_density.
Ignore warnings in included files.
Pull location recording out of node handler.
Fix exmaple.qlr.