Introduce isprint() to print out raw event dumps to ASCII, etc.

(This is an extension to upstream Git's ctype.c.)
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
[ removed openssl.h inclusion from util.h - it leaked ctype.h ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>