ps: minor reformatting and trailing whitespace elimination

This patch mostly reorganizes include files and eliminates
some useless trailing whitespace.

It also adopts the standard procps-ng unconditional approach
to nls initialization.

ps/ps.1

@@ -1085,7 +1085,7 @@ class	CLS	T{
 scheduling class of the process.  (alias
 .BR policy , \ cls ).
 Field's possible values are:
-.IP "" 2	
+.IP "" 2
 \-	not reported
 .br
 TS	SCHED_OTHER