* Set dimensions properly of images on initialization.

Fix for #3203

Image nodes were assigned the default size on initialization, leading to very compressed images.
This fix adjusts the default size as soon as the images used have been loaded.

The approach for dealing with this has been adapted from `CircularImage`.

* Fixed tabs

* Consolidated common code for drawing in nodes

* Consolidated updateBoundingBox(), default version

* Setting bounding box margin in separate method

* Add warnings and errors for image loading

* Fixes and commenting for image loading

* Fix typo

* Small fixes due to review

* Network: use separate refresh indicator in NodeBase, instead of width parameter

* Added usage of iBaseNode.doRefresh to image shapes.

* Rearranged code in NodeBase.needRefresh()

* Fixes for review

* Removed strange link

* Added 's' in needsRefresh(); typo fix

* Fixes for review, code cleanup

* Modified ratio calc to original working.

* Made code in CircularImage.resize() more sensible.

* 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

* element characteristic changes
* assume edge color inheritance is correct before choosing
* Adjust nodes’ chosen’s boolean -> bool
* Need to get user-reset size
* make example edges thicker for more noticeable shadow
* preemptive ES6 fix (see #2500/#2501)
* documentation for the feature that was previously overwritten

* Multifont node and edge labels
* adjust documentation
* rework mod-font property inheritance
* Node max/min widths, min heights; Edge max widths
* Accumulate sizes correctly for unconstrained multipoint labels
* handle font.multi when groupOptions.font is not declared
* propagate label fonts on changes, not just creation
* Allow top-level constraint numbers
* accumulate width and empty lines appropriately

unified border calculation. Needs to be centralized to avoid duplication.

Changed shapeProperties.borderDashes type description from "Object or Boolean" to Array or Boolean".
Merged circularImageWithDashedBorder example into shapesWithDashedBorders example.
Added enableBorderDashes and disableBorderDashes function calls to Database.js, Ellipse.js and Box.js, to enable/disable dashed borders.