Updates to Node.js error reporting have caused tests to fail due to them
being hardcoded to expect a certain format that has since changed. Fix
by making Node.js create the error message for us.
Move the code for loading plugins infos from Node.js packages into a
separate module in order to break it out from lib/plugin.js which is
also used on the web interface side. This resolves a warning of using
an expression with require on the webpack build.
Hornwitser