Fix for #3367

Changes:

- Clustered nodes with shared connections are added to the same cluster
- joinCondition value `null` handled as `undefined`
- Fixed bug on adding clusters if joinCondition present and returns true

Unit tests have been added to `Network.test.js` for these changes.

* Added commenting for options, refactored choosify()

* Refactored updateLabelModule()

* added comment at node creation

* Completed fix for #3350

* parseOptions() different handling for bridged/extended; unit tests for reversal of options

* Fixes on linting and unit testing

* Enable unit testing for module Network

Adds mocks for certain components, in order to let module `Network` be run in unit tests.

Changes:

- Create a mock object for `hammer.js` when running browserless. The inspiration is taken from [here](https://github.com/uber/deck.gl/pull/658)
- Create a mock function for `window.requestAnimationFrame()` when running browserless in `network/modules/CanvasRenderer.js`
- Added unit test for `Network` to show that unit testing for it now works
- Fixed naming of container in `test/Graph3d.test.js`

Since `hammer.js` is also used in other modules, this fix is potentially an enabler for full-module unit tests for those as well.

* Cleanup unit test Network

* Fix for unit test

* Added example networks to unit test

* Fix error in loading disassemblerExample

* Network unit test final fixes

* Adjusted comments

* First working version of updating clustered edge

* Added fix for #1315 as well

* Enable unit testing for module Network

Adds mocks for certain components, in order to let module `Network` be run in unit tests.

Changes:

- Create a mock object for `hammer.js` when running browserless. The inspiration is taken from [here](https://github.com/uber/deck.gl/pull/658)
- Create a mock function for `window.requestAnimationFrame()` when running browserless in `network/modules/CanvasRenderer.js`
- Added unit test for `Network` to show that unit testing for it now works
- Fixed naming of container in `test/Graph3d.test.js`

Since `hammer.js` is also used in other modules, this fix is potentially an enabler for full-module unit tests for those as well.

* Cleanup unit test Network

* Added unit test for fix issue #1218

* Adding test for #1315 - Interim save

* Completed unit test and fixes for #1315

* Added fixes for #1291

* Added unit test for #1219

* Added header comment for Clustering.js, small fixes

* Fix for unit test

* Added example networks to unit test

* Fix error in loading disassemblerExample

* Network unit test final fixes

* Fixes for linting

* Fixed essential typo

* Fixed linting error

* Fixed unit test

* Fixed unit test again

* Proof of concept with copied options + handling from network

* Added unit test for Graph3d, for checking default syntax; completed def's of all options, autoByDefault not handled yet.

* Fixes for options in playground example

* Added onclick options to graph3d documentation

* Fixes in graph3d examples

* Final fixes for option definitions in Graph3d

* Fixed handling of 'undefined' in options, enhanced graph3d unit test

* Disabled console output in graph3d unit test

* Upgrade webpack module

* Fix mergeOptions() and add unit tests

* Removed comment

* Code cleanup, for better understanding

* Further refactoring; text processing to blocks in separate method

* Added unit test for labels - tests standard text and html tags

* Labels added unit tests for markdown

* Further refactoring; made multi and regular handling more congruent

* Interim save, not there yet

* Unit tests done, first working version

* Added test case with two big words

* Code cleanup

* Break up huge words into lines.

* Restore unrelated code change

* Added unit test for Validator, minimum viable version.

* Added test-console to package list

* Completed minimum viable unit test for Validator

* Added Validator unit test for explicit 'undefined'

* Add unit tests for Graph3D issue

This adds a unit test for PR #3255 which fixes #3251.
The unit test will fail without the PR merged.

**NOTE:** This also adds module `canvas`, required for the unit test. This module
proved to be quite fickly to install properly. During reviewing, please pay special
attention to the proper installation of this modul. I.e. do following to test:

```
> npm install                      # If no errors, continue
> npm test /tests/Graph3D.test.js  # Run unit test isolated
```

* Fix for travis-cl

* Add giflib to travis test definition

* Add libgif to travis test definition - take 2

* Proper setup and teardown for jsdom-global

* Minor fixes and cleanup

* Fix for timeline TimeStep.roundToMinor - resolving issue #3105

* Adding some tests for TimeStep

* Properly handle newline escape sequences in strings for DOT

* Adjust comments in code

This takes a more robust approach to produce the list of class names.

Somewhat more complicated setup, associated with the need for a real window.

Clean up and centralise edit status for Timeline Items.

* maximum width constraints must be violated by long words. Fixes #2604.

* chore: moved examples/network/_tests/maximumWidthEdgeCase.html to test/network/

Fixes default end, and reduces duplicated code. Adds tests.

* Should fix issue #2100 and fix another issue we discovered around clusterByConnection leaving phantom edges.
* fixed a wrong variable name
* fixed DataView.test.js assert
* Update Canvas.js
* remove whitespace; remove end of file newline on Canvas.js
* strip end of file newlines
* fixed styling. spacing, semicolons, line length

- Added parentCentralization option for hierarchical layout.

added example. Improved handling of options for hierarchical view.

- Fixed #1528, #1278, avoided ID's being cast to string for methods that return ID's as well as storePositions casting to string.