ImageGetLinkType returns the link type.
nLinkType = ImageGetLinkType(hImg)*nLinkType* is one of the following values:.
||Embed picture in the document.
||Link to a file with the picture. Only the file name is saved in the document.
||Embed the picture in the document. When the UniPlot document is opened it checks if the embedded picture is current. If the embedded picture is older than the external picture file, the picture is reloaded.
In UniPlot 3.x only nLinkType = 2 is supported. The other options will
be available in UniPlot 4.x.
Identifies the image.