Updated notification badge

[marmat]

\ DO NOT MERGE THIS YET; I ACCIDENTALLY GOT AN OLDER VERSION OF THE BACKGROUND_CONTROLLER **

I changed the looks of the notification badge a bit so that it looks like the original Google+ notification badge (i.e. rounded corners and a stroke around them, see images for comparison). Furthermore I made the badge being rendered as inactive whenever the count is a non-positive number (if this is not desired, make sure to set newItem to false when calling the method with a count of zero, I didn't look where the method gets called).

Please see the comments in my commit; maybe the method for drawing a rounded rectangle should be added to the Canvas context prototype somewhere else.

[mohamedmansour]

Heya martin, this is great! Beyond awesome, very good job! Exactly what i am looking for!

Some comments.

• Can you make another class named nptification badge renderer or anything you want that encapsulates all this? Becausete logic of nptification bade is getting large. Or create a static methpd class for canvas context helpers, your pick
• Can you please rebase before you do a pull request, i have seen you touch some code that jphn and i were working on