Bug 977056 - [Dialer] Visual discrepancies: Call ended view under conference call participants list

The need for this is because of the way we currently deal with call nodes when they are added to or removed from a conference call. When a call is added to a conference call, the call node is moved from the main call screen page to the conference call details overlay. When the conference call ends, any pending ongoing calls are moved back from the conference call details overlay to the main call screen page. The problem is that if the conference call details overlay is shown, this moving should not be made right away but wait for some seconds (during which the "Call Ended" text and call duration is being shown) or until the user taps on the hide button. I opted for the cloning of the node in the participant list to provide the user with a better user experience and to avoid the flicking caused by this node movement from the conference call details overlay to the main call screen (which can be really noticeable).