`fatalExit()` now provides more information to the logger.
An exception while closing the programmer no longer obscures another exception that caused the close in the first place. (An error closing the programmer is now logged as a warning and then ignored.)
Common now does `toX4()` for `Collection<Short>`.
Corrected the loading routine in `HexFile` by making a line clear instead of setting it to `null`.
Light refactoring in `ProgrammerPort`.