SystemJS Version 6.10.0

Features

• Refactor amd.js to only call System.register. Resolves #2331. Add Error #9 and Warning W6 to errors.md documentation. This is a significant refactor but should not change behavior. (#2335)
• Add package.json to package exports (#2317 @mk-pmb)

Patches

• Do not throw errors when _export(null) is called. Resolves #2332. (#2334)