fix a bug in LWP 'usc-cn' can not be recognized correctly.

gistfile1.pl

# fix a  bug in LWP   'usc-cn' can not be recognized correctly.
#  
#  when i  use  method  HTTP::RESPONSE::decoded_content ,that can not decode 'usc-cn' html 
#  but it  use 'iso-8859-1' to decode html.
#  though   'iso-8859-1'  is  a universe code , the decode method can work well.
#  but    HTTP::RESPONSE::content_charset  can not get the right code name  .
# 
#   there are two causes   
#　　　　　　　　　one  is   Encode::Encoding::mime_name can not get usc-cn,  usc-cn is not in the IANA charset name list.
#                  the other is   HTTP::RESPONSE::decoded_content havdn't implement  usc-cn decode,we only can use iso-8859-1 to replace.
#      by  shalk 2013-6-11
#
#   example code 
use 5.010;
use strict;
use LWP;
use Encode;
use IO::HTML;

my $line= '69.123.123.123';
my $url="http://ip138.com/ips138.asp?ip=$line&action=2";
my $browser = LWP::UserAgent->new;
my $response = $browser->get($url);
if($response -> is_success) {
  #print "res:",$response,"\n";
	my $html1 = $response -> decoded_content;
	say "----------------";
	say 'content_charset:',$response->content_charset;
   if( $html1 =~  m/<li>(.*?)<\/li>/){
		print "line=$1\n";	
	}
}
#########################################################################
#  fix code  in lib 
#  we can make a litte  modification in lib code
#  first place  /HTTP/Message.pm
#  about  line 204
#########################################################################
my $encoding = IO::HTML::find_charset_in($cref, { encoding    => 1,
                                                  need_pragma => 0 });
return $encoding->mime_name if $encoding;
      #changed into     
return   IO::HTML::find_charset_in($cref, { encoding    => 0,
                                            need_pragma => 0 });

#########################################################################
#  second  place  /HTTP/Message.pm
# about  line 364
#########################################################################
elsif ($charset eq "us-ascii" || $charset eq "iso-8859-1") {
 # changed to 
elsif ($charset eq "us-ascii" || $charset eq "iso-8859-1"||$charset eq "euc-cn") {
	
# now we can