cLock: check calendar visibility on start of CalendarWidgetService

(see also http://review.cyanogenmod.org/#/c/33973/)

Change-Id: I24e250db779c343b82fe71469827be2bc565a09d
cLock: optimize widget display if parts are not visible

Change-Id: Icc49411b20f27d9ae254ce672e36cb87f2a1602e
Merge "cLock: optimize widget display if parts are not visible" into cm-10.1
Merge "cLock: check calendar visibility on start of CalendarWidgetService" into cm-10.1
Merge remote-tracking branch 'upstream/cm-10.1' into cm-10.1