Play nicer with merged contacts

[arlolra]

See: https://trac.torproject.org/projects/tor/ticket/17833

[azadi]

I suggest we disable contact merging and that takes care of all related issues. It's not a useful feature or maybe I am not seeing all possibilities.

[arlolra]

I still need to fix it for use in Instantbird.

[azadi]

Oh right, sorry.

[arlolra]

There's some discussion here: TheTorProject/tor-messenger-build#3

[arlolra]

Also, possibly related is #44