Merge pull request #1 from xyz32/master

Change update timer to 500 ms. According to the sampling theorem (Nyquist sampling theorem) the sampling frequency has to be at least double the source signal.
Merge branch 'master' of git://github.com/xyz32/timekeeper into xyz32-master
Not everywhere renamed.
year AlignHCenter
let the user select year format
week background
change week_day
changing the format of the year through the state
save year format state