OMSVGSVGElement.getElementById() doesn't work in Safari

[borismuzychuk]

Hello!
OMSVGSVGElement.getElementById() method returns null on Mac OS X EI Capitan 10.11.6 + Safari 9.1.2 or higher, even if the element exists with such id.
Such behavior doesn't reproduced in other browsers and operation systems.

Sample code
`private OMSVGSVGElement svg;
...
ResourceCallback callback = new ResourceCallback()
{

    @Override
    public void onError(ResourceException e)
    {

    }

    @Override
    public void onSuccess(SVGResource resource)
    {
        svg = resource.getSvg();
        findSVGElementById();
    }

};

...

public void findSVGElementById()
{
...
OMSVGElement svgElement = (OMSVGElement) svg.getElementById("I exist");
// svgElement is null in Safari
...
}`

Only one element has such id.
Tested with v0.5.10 and v0.5.12