patch 8.0.1108: cannot specify mappings for the terminal window

Problem:    Cannot specify mappings for the terminal window.
Solution:   Add the :tmap command and associated code.  (Jacob Askeland,
            closes #2073)
diff --git a/src/gui.c b/src/gui.c
index 97fac50..f714d7a 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -1101,7 +1101,7 @@
 	 * When in a terminal window use the shape/color specified there.
 	 */
 #ifdef FEAT_TERMINAL
-	if (use_terminal_cursor())
+	if (terminal_is_active())
 	    shape = term_get_cursor_shape(&shape_fg, &shape_bg);
 	else
 #endif