public static function incrementFilename($path){
		$i = 1;
		$dir = dirname($path);
		$filename = basename($path);
		if(preg_match('#^(\d+)-(.*)$#',basename($path),$matches)){
			$i = (int) $matches[1];
			$filename = $matches[2];
		}
		do {
			$target = rtrim($dir,'/').'/'.self::cleanFilename($i++.'-'.$filename);
		} while(file_exists($target));
		return $target;
	}