This adds the ability for geometry sets to store build settings that can
be automatically applied when they are loaded. This should allow sharing
of .gset files to demonstrate problems with certain settings on certain
files. It also allows people to diagnose problems more easily by being
able to dump their own triangle meshes and settings and load them in the
demo, with all of its visualization options. .gset files can be created
from the current mesh and settings by pressing the 9 key, which will
generate it in the same folder as the input mesh.
Also converts more of the demo to use STL.
- added layer based heighfield partitioning
- the method is a bit slower than monotone partitioning, but does not
suffer from the long thin ploys
- the method partitions the heighfield into non-overlapping areas, but
does not try to resolve holes
- improved contour hole merging so that it can properly handle all
kinds of holes
- improved polygon triangulation to handle overlapping segments
- improved small and long polygon detail mesh generation
- updated samples to include all 3 partition methods and little
documentation to help to choose between them
