Updates image size of CSS property
@param {IEmmetEditor} editor
function updateImageSizeCSS(editor) {
		var offset = editor.getCaretPos();
		
		// find tag from current caret position
		var info = require('editorUtils').outputInfo(editor);
		var cssRule = require('cssEditTree').parseFromPosition(info.content, offset, true);
		if (cssRule) {
			// check if there is property with image under caret
			var prop = cssRule.itemFromPosition(offset, true), m;
			if (prop && (m = /url\((["']?)(.+?)\1\)/i.exec(prop.value() || ''))) {
				getImageSizeForSource(editor, m[2], function(size) {
					if (size) {
						var compoundData = cssRule.range(true);
						cssRule.value('width', size.width + 'px');
						cssRule.value('height', size.height + 'px', cssRule.indexOf('width') + 1);
						
						require('actionUtils').compoundUpdate(editor, _.extend(compoundData, {
							data: cssRule.toString(),
							caret: offset
						}));
					}
				});
			}
		}
	}