[SUGGESTION] Allow users to appear online to specific people or servers.

My boyfriend uses the 'appear offline' status all the time, because certain friends of his will pester him constantly for as long as he's online. This is a problem, because while they don't know when he's online now, neither do I, and our timezones make it super hard to guess. 

I am suggesting a feature where there could be an option to change your status depending on the server you're in, rather than for your account as a whole - or an 'appear online to this person' option.

I think this would be really beneficial for a lot of people who aren't comfortable coming off Do Not Disturb or Offline for everyone, but would do so for certain friends.