Tweak some .gitignore entries.
Set up to use @terraswarm/gdp npm module. Various cleanups to gdpjs.js
Removed lang/js/node_modules/ directory. Its contents will be built dynamically using npm install . See lang/js/Makefile .
Modified gdp/lang/js/Makefile to use "npm install" for each required Node.js module. The npm installation directory, node_modules/, is now not included in this repository.