Stricter ABSPATH page access check and CRLF fixes
Give translatable strings some air
Introduce singleton pattern. Use guard() to get the instance
More air between braces
Make use of new class globals. Rewrite load_textdomain usage
Setup Guard_MS base class in new includes folder
Move all MS related logic to Guard_MS. Also include the MS file
Rename Guard_MS file to guard-multisite.php