* Enable linting for Travis

Since all code has been linted (thanks **TODO**!), it is now safe to enable linting for Travis.

Some cleanup actions have been performed; notably the additional `gulp` tasks for modules has
been removed. Since all code has been fixed for linting, these are not useful any more.

* Force linting error to check travis working

* Travis works! Remove forced linting error

* 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 typo in #3262, ending `*/` of a block comment was missing.
Also disabled new item `no-useless-escape` for linting, because this triggers a bit too often for comfort.

* First working version of eslint enabled with gulp

* Tryout of eslint with graph3d files

* Cleanup of gulp and eslint files.

* Completed test by linting graph3d

* Disable travis linting for now

* Remove global cmd param from .travis.yml

* Add C++11 and canvas module for travis tests

* Added libgif, updated version gulp-clean-css

* Update version webpack

* Force versions minimatch, graceful-fs; fixes for upgraded webpack

* Force version minimatch through travis.yml

* Fix comma's in json

* Add extraneous modules to package.json; final attempt at forcing versions of minimatch and graceful-fs

* Final changes module versions

* Fix due to linting

* Fix typo in package.json

* Upgrade eslint