1)  On systems running Upstart, shorewall-init cannot reliably secure
    the firewall before interfaces are brought up.

2)  The 'enable', 'reenable' and 'disable' commands do not work
    correctly in configurations with USE_DEFAULT_RT=No.

3)  Start/restart/reload fails under the following conditions:

    - DOCKER=Yes
    - The firewall has been started previously with Docker running.
    - The start, restart or reload command is executed with Docker not
      running.

    Workaround: rm /var/lib/shorewall/.nat_OUTPUT

    Corrected in Shorewall 5.0.6.1

4)  In Shorewall 5.0.6, the 'check -r' command dies with an assertion
    failure.