meteor-sharejs fork

[edemaine]

Fork https://github.com/mizzao/meteor-sharejs to resolve

• Need to declare use of ecmascript mizzao/meteor-sharejs#86
• Update to codemirror 5.25.0 mizzao/meteor-sharejs#87
• Or more generally, divorce included codemirror, and support the app's version from NPM, via peer npm dependencies.
• Or perhaps we can use meteor-sharejs without meteor-sharejs-codemirror?
• Ideally move from Meteor package to NPM package to support dynamic imports (Bundle optimization #218)

Fork started here: https://github.com/edemaine/meteor-sharejs