Make internal proj constructors private
Minify CSS
Merge pull request #2346 from tschaub/clean-css

Minify CSS.
Remove unnecessary linting of generated exports file
No reason for build.py to run generate-exports.js

The doc task does not use the generated exports.js file.
Unused JAR executable
Unused JAVA executable
Merge pull request #2342 from tschaub/private-proj

Make internal proj constructors private.
Merge pull request #2343 from tschaub/build-cleanups

Build cleanups.