Add identicons
Fix signal bars
fix possible buffer overrun and memory leak

Use snprintf instead of sprintf and fclose() before return.

Change-Id: I3ed193464cc0dc90e9935ae19162667ad367628b
SystemUI: don't crash when user disable default apps

If the user has disabled the default clock or calendar application,
System UI will crash when the user clicks the Clock or Calendar
from the notification bar. This patch fixes the issue.

Change-Id: Icdc3679cdd35b5b3a24086e1ada67d0defabc5cb