Fixed a bug in Fritzing file, added a pattern for drilling

- fixed a wrong wiring in fritzing files
- added a printable pattern used to ease drilling when 
making a "wooden-box-wrapped" version of the clock
Cleaned code

- changed power-on time to 12:00:00
- power-on self test is now shorter (less than half a second)
- time advance has been compensated (1.6s every hour)