SimClock will no longer remember that it was paused last time

Previously, if the sim clock was paused, the pause is remembered across restarts of KStars. I think this causes issues for users--e.g. if you have it paused, the Ekos scheduler will not start for a future condition because the time never changes. It is not intuitive--users may not remember to unpause at the end of some session, and will likely not notice it's paused. Users likely assume a restart is a fresh start.

This MR causes KStars to always start the sim clock when KStars starts (unless the old command-line flag --paused is used).