Add a readable header to binary files

[BerndDoser]

The binary file formats described at https://github.com/HITS-AIN/PINK/wiki/Description-of-the-binary-file-formats will be expanded by a readable header for data information and comments. For separating the readable text from binary data the ASCII NUL character '\0' will be used. If a SOM is initialized with a SOM-file, the header will be copied to the resulting SOM-file.

[BerndDoser]

Using a ASCII NUL character '\0' to separate a readable header text before the binary data would be force to change existing PINK files. To avoid this and to be backward compatible within the next minor release, I change the syntax for the header section: All lines starting with '#' at the beginning of the file will be ignored.