smart cover: show it when closing display while on keyguard

currently if you are on the keyguard and close the smart cover, the display
will turn off.

only turn it off, if we are not on the keyguard.
screen turns off after the default smart cover timeout

Change-Id: I889dd04b2b5223c3f239f41cc3bf097541c0497e
Smart Cover: update appearance

d38e3e5 smart cover: reduce textsize of the clock and status lines to fit better
3639d58 smart cover: change left and right padding of the content
0b74ec0 smart cover: reduce space on top
3bae23f Smart Cover: update appearance
SmartCover: fix for displaying missed calls and unread messages together

increase the size of the clock slightly