New releases, branches

[Murray Cumming <murrayc murrayc com>]

I've made some branches and made some releases from them:
https://github.com/libxmlplusplus/libxmlplusplus/releases

These are all parallel-installable, with separate ABI names.


* libxml++ 3.2.0 is from the stable libxml++-3-2 git branch:
https://github.com/libxmlplusplus/libxmlplusplus/releases/tag/3.2.0

It has some fixes that had been in git, but there hadn't been a tarball
release since 2016.

This is still the libxml++-3.0 API.


* libxml++ 3.9.1 is from the libxml++-4-0 git branch:
https://github.com/libxmlplusplus/libxmlplusplus/releases/tag/3.9.1

It is the first actual tarball release that uses the unstable glibmm
(currently glibmm-2.64). It has the same fixes as 3.2.0 plus some minor
API changes.

This is the libxml++-4.0 API. This might not be useful to anyone.


* libxml++ 4.9.1 is from git master.

This removes the glibmm dependency. For now it has a simple
xmlpp::ustring alias to std::string.

This is the libxml++-5.0 API.

-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com