source. Using an external clock source (esp. the real-time clock) did not
work. This might as well be a local problem (e.g. hardware).
- Provide some dummy implementations in order to fix the build.
* support for multiple ports: (extended interface with 'port' parameter)
* new function: rs232_redirect_stdout that allows you to redirect stdout
to a serial port
- In order to implement support for other MCUs, adopt a copy of
rs232_atmega128.h
