Mint 15: Website-unavailable.com hijack removal

A quite annoying problem:

Internal webservers on the local network did not get enough time to respond to requests before Google Chrome redirected the user to website-unavailable.com.

At first I thought it was a feature from the local DNS and that I had OpenDNS configured as name servers.

But then I found this thread:
http://forums.linuxmint.com/viewtopic.php?f=90&t=128529

It turned out that OpenDNS was configured as default "fallback" in default in Linux Mint 15! So the local DNS was probably not used at all, it was overriden by OpenDNS. Not how I wanted it.

I did as the thread above suggested to fix this:

Edited and commented out OpenDNS in the following files:
/etc/resolvconf/resolv.conf.d/tail

And:

/etc/resolv.conf

Note that you cannot only edit resolv.conf as this probably will be overwritten.