Thanks to Thomas Otto for pointing out problems with the clock code in
examples and his clock routine implementations. Based on that the most
common clock combination routines were added to the library and all
routines in examples setting up the clock replaced with calls to that
functions.
Now all examples are including only the modules they really need. Also
each header file of the library is including only the necessary headers
making it possible to use these modules in parallel with other
implementations that may collide with the definitions in other modules.