Added OS detection so that the correct echo escape character is used on OS X

Signed-off-by: Florian Bogner <florian@bogner.sh>
Disabled last login information on OS X

Signed-off-by: Florian Bogner <florian@bogner.sh>
Fixed detection of good breakout binaries

Signed-off-by: Florian Bogner <florian@bogner.sh>
Removed further -r arguments for xargs as this paramteter is not available on OS X

Signed-off-by: Florian Bogner <florian@bogner.sh>