Fix and/or simplify terminal initialization files.

Fix and/or simplify terminal initialization files.

* lisp/faces.el (tty-create-frame-with-faces): Set up faces and
  background mode only after the terminal has been initialized.
  (frame-set-background-mode): Handle the 'background-mode terminal
  parameter.
  (tty-run-terminal-initialization): Add type option.

* lisp/term/README: Update.
* lisp/term/rxvt.el: Simplify.
* lisp/term/xterm.el: Simplify and fix.
* lisp/term/*.el: Simplify and fix.

git-archimport-id: lorentey@elte.hu--2004/emacs--multi-tty--0--patch-564