Recent contacts view on home screen

Hi guys, I've added some logic to create the recent contacts view. It took me a while and a lot of searching to create this functionality. With this branch, recent contacts are parsed in home.js, and listed out in descending order by the number of occurrence (the more common a name appears on screen, the higher it is on the list).
The number of contacts is limited to 5 and the user's own name is omitted from the list.

 However, there is still a part where I still don't understand (I know, I coded this up O_o). Particularly between line 124 to 134 of home.js. 
Hopefully y'all can shed some light on this and review the PR in the meantime!

Cheers! :smiley: 
I see!

Except that when use ``el.dataset.id`` in the _.unique function, it throws an **Uncaught TypeError: Cannot read property 'id' of undefined** error. So I had to change it ``el.userId``, which grabs the value of the userId key from each object inside the array. 

This change also made the ``a.dataset.id`` not work as expected. But changing them to ``a.userId`` doesn't seem to produce the right results though. I mean the names show up without any errors thrown, but the ordering functionality is lost.