fixes #2685

* Added showX(YZ)Axis to Graph3d

* Added show_Axis options to docs and playground example

* Resolved merge conflict

* Added show_Axis options to docs and playground example

* change setCustomTimeTitle title parameter, Now could be an string or a function
* Fixed indent and spacing

Related to: https://github.com/almende/vis/pull/2618
Related to: https://github.com/almende/vis/pull/2620

* Replaces instanceof Object checks with typeof to prevent cross tab issues.

* Adds missing space.

* removed NOTICE file

* updated license date range to include 2017

* chore(docs): updated support team members

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

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

fixes #2640

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Fix zoom below 1ms bug

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Fix mousewheel while dragging item bug
* Return removed lines

Using the 'directed' sort method, the layout engine seemed to ignore treeSpacing (or only apply it to the first tree). This would also lead to trees colliding with one another, and having their nodes tangled in space. This complaint surfaced in a couple bugs, including #2494. This should be a step toward fixing that. For whatever reason, this code never runs when using the "hubsize" sort method.

If you want to integrate the vis.js sources in a project you need some babel-pugins.

see #2353

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

* self reference edge should now appear in all cases
* add checks for shape width being NaN to get correct circle data
* reorder resize arguments in Diamond, Dot and Star

* fix #2613 with if statement, and null for pointer value rather than referencing it when undefined

* removed if statement, since not needed, and updated documentation to note the null pointer property in certain conditions.

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example

* updated HISTORY.md for v4.18.0
* bumped package version to 4.18.0

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix right click button bug when dragging item

* fix(graph2d): fix #2500 for graph2d; improves #2580

* fix(DataSet): make sure the right id-type is used internaly

This fixes a fixed strange string-number conversion issue.
It can happen that id "0" !== 0 what causes #2580.

fixes #2580

* address IE11 issue 'Symbol' is undefined with babel-polyfill  

https://github.com/almende/vis/issues/2560

* address IE11 issue 'Symbol' is undefined with babel-polyfill

https://github.com/almende/vis/issues/2560

* address IE11 issue 'Symbol' is undefined with babel-polyfill

https://github.com/almende/vis/issues/2560

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Fix #2538

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code