clarify compatibility with ufw

[adrelanos]

We are wondering, is corridor (as a host firewall #3) compatible with ufw? Has this been tested? Is that discouraged?

Please clarify. Then documentation will perhaps recommend to uninstall ufw first. (And I'd add a Conflicts: for Debian packaging. (#10))

[rustybird]

I've never tried ufw.

[adrelanos]

I wonder if combination with ufw should be discouraged then?

I think unless one is intimate how ufw works, with its instructions on how it can be combined with other iptables rules, ufw is a recipe for disaster. It might either break what ufw is doing, or what corridor is doing, or even both.

ufw documentation on combining ufw with other iptables rules at https://wiki.ubuntu.com/UncomplicatedFirewall#Advanced_Functionality tells me, corridor and ufw cannot be easily combined.

//cc @HulaHoopWhonix