ED+ max amount of program lines

[Sebastiaan Fisscher]

The max amount of line number in ED+ is somewhere arround 1 million, which is pretty impressive.
However, when you hit the 1 million mark, the program freezes up and cannot be closed by normal means. It would be more user friendly to at least give an error message, or some other form of feedback that the user has reached the maximum number of program lines.