Rotary-Encoder-FreeRTOS-00

First exercise in distributing the generation of radio station indexes over separate tasks in FreeRTOS.

This project now has:

1. A reasonable separation of FreeRTOS task functions and header files.
2. Use of a mutex to "transport" values that are hold in a struct over multiple tasks.
3. A clear insight into how to define, declare, initialize and use local- and global variables in a project that has several header and program files.