libzip 1.6.0 released

[Thomas Klausner <tk%giga.or.at@localhost>]

Hi!

We've just released libzip 1.6.0.

Changes to the previous version include:

* Avoid using umask() since it's not thread-safe.
* Set close-on-exec flag when opening files.
* Do not accept empty files as valid zip archives any longer.
* Add support for XZ compressed files (using liblzma).
* Add support for cancelling while closing zip archives.
* Add support for setting the time in the on-disk format.


Because of Tomáš Malý the test suite is now running on Windows. Thank
you very much, Tomáš!

Three tests are still failing. We don't understand the problem and do
not have a Windows debugging environment. We'd appreciate help with
getting these fixed. They are:

* buffer-fragment-read.test
* buffer-fragment-write.test
* junk_at_start.test

See e.g.
https://ci.appveyor.com/project/0-wiz-0/libzip/builds/29973574/job/8ef7nfglwvntjpeb

Cheers,
 Thomas