Clock: use mCalendar to get seconds

We haz teh calendar already. No need to create a new one to get the seconds.

Change-Id: Iccfc6e25367ad57a99bf27c29311e260b5e276d8
Signed-off-by: Tianrui Guo <tianrui@pac-rom.com>
Changed battery font to sans-serif

Change-Id: I8e3a62020b75db786bbd24124da0849b2bdad8d7