terminal: use COLORTERM=kmscon as default

We now set COLORTERM to "kmscon" so applications can identify their
controlling terminal. Note that COLORTERM is not used for terminfo/termcap
detection (unlike TERM).

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

src/kmscon_terminal.c

@@ -545,6 +545,10 @@ int kmscon_terminal_register(struct kmscon_session **out,
 	if (ret)
 		goto err_pty;
 
+	ret = kmscon_pty_set_colorterm(term->pty, "kmscon");
+	if (ret)
+		goto err_pty;
+
 	ret = kmscon_pty_set_argv(term->pty, term->conf->argv);
 	if (ret)
 		goto err_pty;