Fix for CIS 6.2.8 (PermitRootLogin)

Don't replace the documentation text!
Fix for CIS 6.2.4 (X11Forwarding)

CentOS 6.4's /etc/ssh/sshd_config has:

    #X11Forwarding no
    X11Forwarding yes

The desire of CIS 6.2.4 is to disable X11Forwarding, so uncomment
the first one and delete the 'yes' one.
Merge pull request #3 from alanorth/syntax_fixes

Syntax fixes