rado port information stored in a text string, not a dictionary

[wb8tyw]

The radio port information is currently stored internally as a string instead of a dictionary.

This allow users to enter in invalid information that can break the parsing of the string.

This also makes it harder to add attributes for the setting the connection.

The serial port connections need settings for software xon/xoff, DSR signal handling, RTS/CTS Handling, and other enhancements.