top: still more tidying up after <pids> implementation

A patch containing the following miscellaneous tweaks:

. remove a function that handled former library errors
[ that function should have gone bye-bye with 3.3.11 ]
[ when those 'wchan' provisions were much simplified ]

. make clearer a distinction between 'new' and 'reset'
[ use PROCPS_PIDS_noop when procps_pids_new() called ]
[ since at that point we are only establishing depth ]

Reference(s):
http://www.freelists.org/post/procps/newlib-for-pgrep,1

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

top/top.h

@@ -590,7 +590,6 @@ typedef struct WIN_t {
 //atic void          at_eoj (void);
 //atic void          bye_bye (const char *str);
 //atic void          error_exit (const char *str);
-//atic void          library_err (const char *fmts, ...);
 //atic void          sig_abexit (int sig);
 //atic void          sig_endpgm (int dont_care_sig);
 //atic void          sig_paused (int dont_care_sig);