Allow domain names in "Manually add a server..."

The "Manually add a server..." function only accepts numeric addresses. This made a certain sense when it was introduced, since the remote allowed direct input of numbers, but alphabetic input required something like the ouija board. Nowadays, though, we can input alpha directly in several ways.

Numeric IP addresses are 1) more difficult for end users to find and remember, and 2) more expensive for providers. This feature could get more use if it didn't depend on numeric IPs.