phpan/phpstan clean up runs, minor update to DB\IO

DB\IO dbReturn method has a third parameter to set read only assoc and
not number data from the query

Install basic composer for trying out psalm

setting phpan/phpstan for basic static checking and do basic clean up on
all of the files

www/lib/FileUpload/Core/qqUploadedFileXhr.php

@@ -38,7 +38,7 @@ class qqUploadedFileXhr
 		if (isset($_SERVER["CONTENT_LENGTH"])) {
 			return (int)$_SERVER["CONTENT_LENGTH"];
 		} else {
-			throw new Exception('Getting content length is not supported.');
+			throw new \Exception('Getting content length is not supported.');
 		}
 	}
 }