Fixed tty faces during combo sessions. Plus other assorted bugfixes.

Fixed tty faces during combo sessions.  Plus other assorted bugfixes.

lisp/startup.el (command-line): Always call tty-register-default-colors.

src/dispextern.h (delete_tty): Added missing prototype.

src/keyboard.c (read_avail_input): Close display gracefully if needed.
Kill Emacs if the last display is to be closed.
(tty_read_avail_input): Don't call delete_tty and don't signal hangup here;
return -2 instead to indicate the non-transient failure to read_avail_input.

src/term.c (delete_tty): Removed superflous wiping of the deleted
frames' output_data field.
(delete_display): Check for and close live frames that are still on the display.
src/termhooks.h (read_socket_hook, delete_display_hook): Added detailed comment.
src/xfaces.c (realize_face): Create a dummy face for the initial frame.
(Reported by Robert J. Chassell (bob at rattlenake dot com).)

git-archimport-id: lorentey@elte.hu--2004/emacs--multi-tty--0--patch-61