Right now we have a hack that adds a mock "New User" account into the
model, which doesn't contain any data. This user is alawys there and it
is always in the bottom.

So, when we add a new user, what we are doing is updating the information
from the "New User" to the information of the newly added account, and
adding a new "New user" account at the bottom.

[0] - user1
[1] - user2
[2] - user3
[3] - New User

model->UserAdded

[0] - user1
[1] - user2
[2] - user3
[3] - user4 //We have to notify 3 has been changed
[4] - New User //we have to notify 4 has been added

Since we don't know if we are going to keep "New User" around, it is not
worth it to move it into a Proxy Model (where it belongs). Will refactor
the code once we decide what to do.