Returns image dimensions for source
@param {IEmmetEditor} editor
@param {String} src Image source (path or data:url)
function getImageSizeForSource(editor, src, callback) {
		var fileContent;
		var au = require('actionUtils');
		if (src) {
			// check if it is data:url
			if (/^data:/.test(src)) {
				fileContent = require('base64').decode( src.replace(/^data\:.+?;.+?,/, '') );
				return callback(au.getImageSize(fileContent));
			}
			
			var file = require('file');
			var absPath = file.locateFile(editor.getFilePath(), src);
			if (absPath === null) {
				throw "Can't find " + src + ' file';
			}
			
			file.read(absPath, function(err, content) {
				if (err) {
					throw 'Unable to read ' + absPath + ': ' + err;
				}
				
				content = String(content);
				callback(au.getImageSize(content));
			});
		}
	}