Log Message:
Update to 1.13:

* Version 1.13 (released 2009-03-06)

** libidn: Use a LD version script on platforms where it is supported.
Currently only GNU LD and the Solaris linker supports it.  This helps
Debian package tools to produce better dependencies.  Before we used
Libtool -export-symbols-regex that created an anonymous version tag.
Libidn uses -export-symbols-regex if the system does not support LD
version scripts, but that only affect symbol visibility.

** libidn: Compiled with -fvisibility=hidden by default if supported.
Currently only GCC supports it for ELF targets.  This hides internal
symbols and has other advantages, see
<http://gcc.gnu.org/wiki/Visibility>.

** libidn: Compiled with warning flags only when GCC is used.
This avoids the problem that some flags confuse non-GCC compilers, for
example -fdiagnostics-show-option.  Reported by
jens.rehsack@bayerbbs.com.

** doc: The idn_free function is now documented.
Suggested by "Sisyphus" <sisyphus1@optusnet.com.au>.

** API and ABI is backwards compatible with the previous version.