The only packages not fully updated are:
- qunitjs & karma-qunit as that's a QUnit 2.x update that will require some
changes and we'll do that later
- jsdom as we need to first rewrite the test with the Symbol polyfill - newer
jsdom versions don't work with such a hacked Symbol instance
- sinon as the v2 -> v7 upgrade requires to update our unit tests
- uglify-js & grunt-contrib-uglify as latest uglify-js versions slightly worsen
the minified gzipped size
Closes gh-4227
Closes gh-4228
Closes gh-4230
Closes gh-4232
Also, run `grunt npmcopy` to sync the "external" directory with dependencies
from package.json. For example, the Sinon library version didn't match.
Ref gh-4234
Closes gh-4297
All deps were updated except:
* jsdom - tests using a Symbol polyfill are hacky and break with newer jsdom;
we need to re-do them properly first
* qunitjs - versions 1.19.0 & 1.20.0 introduce race conditions to the tests,
making the fail randomly
Those two packages will be updated once issues related to them get resolved.
Fixes gh-2877
