patch 8.0.1592: terminal windows in a session are not properly restored

Problem:    Terminal windows in a session are not properly restored.
Solution:   Add "terminal" in 'sessionoptions'.  When possible restore the
            command running in a terminal.
diff --git a/src/structs.h b/src/structs.h
index 7dc732c..d6959bc 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1706,7 +1706,8 @@
 #define JO2_HIDDEN	    0x0400	/* "hidden" */
 #define JO2_TERM_OPENCMD    0x0800	/* "term_opencmd" */
 #define JO2_EOF_CHARS	    0x1000	/* "eof_chars" */
-#define JO2_ALL		    0x1FFF
+#define JO2_NORESTORE	    0x2000	/* "norestore" */
+#define JO2_ALL		    0x2FFF
 
 #define JO_MODE_ALL	(JO_MODE + JO_IN_MODE + JO_OUT_MODE + JO_ERR_MODE)
 #define JO_CB_ALL \
@@ -1769,6 +1770,7 @@
     int		jo_vertical;
     int		jo_curwin;
     int		jo_hidden;
+    int		jo_term_norestore;
     char_u	*jo_term_name;
     char_u	*jo_term_opencmd;
     int		jo_term_finish;