Remove extra whitespace
Only check syntax if it's not a binary file
Fix (partial) of setting debugged_program
Fix bug in list command.

When at the end of a file, "list-" would not work.
Stop reimplementing instead of testing

That utility method was doing exactly the same thing as the
functionality being tested.
Implement missing test
Refactor list command a bit
Get ready for 3.4.1 release