patch 8.0.0725: a terminal window does not handle keyboard input

Problem:    A terminal window does not handle keyboard input.
Solution:   Add terminal_loop().  ":term bash -i" sort of works now.
diff --git a/src/normal.c b/src/normal.c
index fe1a182..c8e7841 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -7846,7 +7846,10 @@
 nv_window(cmdarg_T *cap)
 {
 #ifdef FEAT_WINDOWS
-    if (!checkclearop(cap->oap))
+    if (cap->nchar == ':')
+	/* "CTRL-W :" is the same as typing ":"; useful in a terminal window */
+	nv_colon(cap);
+    else if (!checkclearop(cap->oap))
 	do_window(cap->nchar, cap->count0, NUL); /* everything is in window.c */
 #else
     (void)checkclearop(cap->oap);