Description of Problem:
If you run multiple X servers on the same machine, and have evolution
running on one of them, you're unable to start a copy on the other display;
the new windows open on whatever display the running copy of evolution is on.

For instance, I have :0 and :1 on my machine; if I start evolution in :0,
it comes up okay. Then if I switch over to :1, and run evolution there, the
splash screen flashes momentarily on :1, and then an evolution session
opens up on :0.

If I want to run a session on :1, I need to kill the one on :0 first (and
then of course, if a :1 session is running, it means I can't open one on :0)

In the case of connecting remotely to a VNC server on :1, it means that I
can't cleanly shut down evolution on the other display, since I don't have
physical access to :0; I have to send it a kill signal, which could be
problematic depending what that evolution session has open (i.e. a half
written message on my screen at work)