Bringing in ImmutableJS 3.8.2

[vickramdhawal]

Bringing in ImmutableJS 3.8.2 which is release under MIT license. Source of immutableJS https://github.com/facebook/immutable-js/releases/tag/v3.8.2.
Also updating the gitignore file to exclude node_modules inside src/JSUtils

[nethip]

Thanks for the PR @vickramdhawal 👍

Did you get a chance to run unit tests?

[nethip]

Also looks like CLA has not been signed that is why the travis tests are failing. Can you signup using this link? Please sign the CLA here http://dev.brackets.io/brackets-contributor-license-agreement.html.

[vickramdhawal]

I've signed up now. I did run all tests, but have to bear with multiple dialogs to get it to completion. Will update once its done.

[nethip]

Thanks @vickramdhawal I have restarted the build.

[nethip]

You can disable the dialog popups by returning from the below function. We will have to figure out other means of handling the dialog popups.
https://github.com/adobe/brackets/blob/master/src/document/DocumentCommandHandlers.js#L1727

[vickramdhawal]

immutableJS is used only by the FileTreeView & the FileTreeViewModel and the tests are passing for both. Unit tests are also passing except for the ones already failing on master.

[swmitra]

Good work @vickramdhawal.

[ficristo]

IMO this fixes the effects and not the cause of the problem.