RFR: 8171524: jar --help doesn't provide information that stdout and stdin can be used as output and input for tool

[Henry Jen]

Hi,

Please review a trivial fix[1] for JDK-8171524.

The fix added a short paragraph about @argfile. Clarify stdin or stdout is used 
if —file is omitted.

It also correct that -h, not -? is for the short option for —help.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/jdk9/8171524/0/webrev/