top: existing 'Inspect' pipe feature now more flexible

Currently, it isn't possible to establish an 'Inspect'
pipe that relies on SIGINT to end. That's because this
signal will also end the parent process (top) as well.

So this patch will temporarily ignore that signal when
processing any 'Inspect' pipe, allowing one like this:

. pipe ^I Trace Calls ^I /usr/bin/strace -r -p %d 2>&1

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

top/top_nls.h

@@ -89,7 +89,7 @@ enum norm_nls {
    YINSP_deqtyp_txt, YINSP_dstory_txt,
 #endif
    YINSP_failed_fmt, YINSP_noents_txt, YINSP_pidbad_fmt, YINSP_pidsee_fmt,
-   YINSP_status_fmt, YINSP_workin_txt,
+   YINSP_status_fmt, YINSP_waitin_txt, YINSP_workin_txt,
       norm_MAX
 };