RFR JDK-8186751: Add ISO-8859-16 Charset support

[Xueming Shen]

Hi,

Please help review the changeset to add the 8859_1 charset support.

issue: https://bugs.openjdk.java.net/browse/JDK-8186751
webrev: http://cr.openjdk.java.net/~sherman/8186751/webrev

The real change to add the charset is

make/data/charsetmapping/charsets
||make/data/charsetmapping/ISO_8859_16.map

The rest files are to tweak the regression tests.

Thanks
Shermna