Make flightrack UI interface more intuitive

[Joern Ungermann]

The flightrack handling should be changed in the following way:

• drop the "name" field and replace that by the filename (confuses many users!)
• highlight active flighttrack in list (bold?) Then the active flighttrack might be removed.
• ask for a name when creating a new flighttrack
• add buttons to "select"and "rename" flighttracks
• change double-click to mean "select"
• maybe add right-click action or similar to rename

[Reimar Bauer]

Duplicate of #217.