Before this commit, the Clock Applet was unaware of when the system resumed from sleep mode (e.g. suspend or hibernate). This meant that, if the user suspended the system and then woke it up some time later, the clock might not show the real current time, but instead would continue to show the time at which the system was suspended for up to a minute after the system woke up. This could be confusing to the user if they peered up at the clock immediately after, say, opening their laptop lid. This commit connects to ConsoleKit or (if available) systemd-logind via D-Bus, and listens for a signal that indicates when the system wakes up from sleep mode. When the system does wake up, the Clock Applet updates the date/time immediately, and also updates all the weather/temperature readings if possible. Note that if logind is missing, ConsoleKit2 is required for this feature to work; the original ConsoleKit lacked the signal required to implement this feature. This should not be a problem since it is unlikely that anyone would even consider using the original ConsoleKit in this day and age.