patch 8.0.0717: terminal feature precence unclear

Problem:    Terminal feature not included in :version output.
Solution:   Add +terminal or -terminal.

src/terminal.c

@@ -24,7 +24,6 @@
  * This will result in screen updates.
  *
  * TODO:
- * - +terminal in features[] in version.c
  * - free b_term when closing terminal.
  * - remove term from first_term list when closing terminal.
  * - set buffer options to be scratch, hidden, nomodifiable, etc.

src/version.c

@@ -618,6 +618,11 @@ static char *(features[]) =
 #else
 	"-termguicolors",
 #endif
+#ifdef FEAT_TERMINAL
+	"+terminal",
+#else
+	"-terminal",
+#endif
 #if defined(UNIX)
 /* only Unix can have terminfo instead of termcap */
 # ifdef TERMINFO
@@ -764,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    717,
 /**/
     716,
 /**/