add background-image property
add background-image property

KonstantinShemyak/cytoscape.js,cytoscape/cytoscape.js,rlugojr/cytoscape.js,rlugojr/cytoscape.js,cytoscape/cytoscape.js,KonstantinShemyak/cytoscape.js,soomin-maeng/cytoscape.js,soomin-maeng/cytoscape.js