converters/libiconv: update to 1.17 release (+)
New in 1.17:
* The libiconv library is now licensed under the LGPL version 2.1, instead of
the LGPL version 2.0. The iconv program continues to be licensed under GPL
* Added converters for many single-byte EBCDIC encodings:
They are available through the configure option '--enable-extra-encodings'.