added ps etimes, miscellaneous top enhancements

ps program
 . etimes added for ELAPSED expressed in seconds
 . time_t used in place of former unsigned long

top program
 . corrected scroll message bug when 'x' toggle on
 . fixed forest view potential missing libflags bug
 . improved 'k' default signal invocation logic
 . enhanced logic for %CPU maximums displayed
 . made signal handling more robust and efficient

ps/ps.1

@@ -1008,6 +1008,11 @@ elapsed time since the process was started,
 in\ the form\ [[DD\-]hh:]mm:ss.
 T}
 
+etimes	ELAPSED	T{
+elapsed time since the process was started,
+in\ seconds.
+T}
+
 euid	EUID	T{
 effective user\ ID (alias\ \fBuid\fR).
 T}