ed: command mode versus ctrl+d

[mknos]

• Fix the error 'Can't "last" outside a loop block at ed line 189', triggered by ctrl+d (eof) after loading a file in ed
• When adding the input() function the "last" statement was missed in the error handling code
• Consistently clear globals before calling edParse(); prevent saved state from previous command input from being used by subsequent commands
• Follow OpenBSD ed and make ^D equivalent to typing the regular "q" command
• Example case: Open a text file and delete 1st line with "1d" command, then hit ^D
• The first time I hit ^D in command mode, edQuit() will print a warning about the modified buffer (called via edQuitAsk())
• When I hit ^D a second time, edQuit() remembers that a warning was already printed, so the program exits

[briandfoy]

changes: treat Control-D as the q command so ed exits gracefully