Vector and raster files for both geom and spacing function

[changliao1025]

Ideally, these two types of datasets should match with each other. If the uses only provide vector files, then they can be converted to raster internally.

[changliao1025]

If the user provides them separately, then maybe a check is needed.
Besides, the configuration file should accept both types of files.

[changliao1025]

A lookup table is needed for the vector-to-raster conversion.

Dataset	Vector	Raster
Coastaline	Natural Earth polygon/polyline	Geotiff
River networks	Hydroshed simplified polyline	Geotiff
Lake boundary	Hydroshed polygon	Geotiff
Watershed boundary	Hydroshed polygon	Geotiff

[changliao1025]

The dataset generation process will be moved into the hexwatershed utility repository: https://github.com/changliao1025/hexwatershed_utility

[changliao1025]

The coastline is a static dataset;
The river networks can change depending on resolution
The lake and watershed boundary will also change with applications.