Common handling for settings with prefix 'default'

Add Italian locale support for timeline

Graph3d: Added fields with special handling to default settings.

added all locals to manipulation example

Thanks @federicoco for providing the translation!

linked user profiles in help files

* removed reference to the style-guide
* added a how-to-help; added a document describing the current maintainer status; fixes #2170; closes #1781
* listing the members of the support team
* use search before creating a new issue
* fixes typos

Added structure for default values

Replaced sin/cos usage in drawAxis() with unit vector

Adds oldData to the update event payload in dataview to match dataset.

Added methods for drawing Y and Z axis labels

Consolidated code for drawing x-axis label

Moved recurring code for StepNumber to start() method

Added method for drawing lines between 3D points

* Removed restriction to allow clusters of a single node; Default functionality remains the same;  Also added new example
* Add documentation for allowSingleNodeCluster, and removed excessive cluster() calls in example.
* Changed documentation as per request.

Translation of all data points to single method.

Fixed getPoint for same node edges

Added 2D line drawing method

* Hide vertically hidden ranged items in groups that are not visible
* Fix misspelling
* Fix examples that do not contain groups
* Add example for vertical hidden ranged items
* Fix indent format in RangeItem
* Fix example
* Fix other examples after addition of vertical hiding range items in groups
* Add case of zero margin axis
* Fix commented out lines in examples
* Fix vertical visibility bug

Network: edge-endpoint 'circle'