top: consolidate logic dealing with resetting a window

This commit just gathers all the logic associated with
resetting/normalizing a single window in one function.

In the future, should the window structure be expanded
to support added functionality, the act of maintaining
it will have been made a little bit easier, hopefully.

(everything is perfectly justified plus right margins)
(are completely filled, but of course it must be luck)

Signed-off-by: Jim Warner <james.warner@comcast.net>

top/top.h

@@ -701,6 +701,7 @@ typedef struct WIN_t {
 //atic void          whack_terminal (void);
 /*------  Windows/Field Groups support  ----------------------------------*/
 //atic void          win_names (WIN_t *q, const char *name);
+//atic void          win_reset (WIN_t *q);
 //atic WIN_t        *win_select (int ch);
 //atic int           win_warn (int what);
 //atic void          wins_clrhlp (WIN_t *q, int save);