This would prevent the build path from leaking into the source code.

Signed-off-by: Markus Volk <f_l_k@t-online.de>

If string arguments are passed into gupnp_service_proxy_action_new, they
were leaked

If a server does not use a well-formatted XML but containing whitespaces
in the content, it was possible to not find the types for some
arguements. Strip the contents, so that it matches up

This is specifically to support GI bindings in easier action creation
than using those awkward lists

Seems "recent" versions of NetworkManager also send notifications for lo
which caused those "cannot bind to 127.0.0.1:xxxxx" criticals on Fedora
38

meson.build:1:0: ERROR: Unexpected "[provides]" section, did you mean "[provide]"?

use xmlReadMemory, also use NONET flat

Move it to prepare_action_msg so it is also available in sync calls, for
handling authentication requests properly.

Fixes #86

Fixes: #85

this allows for cross-compilation.

successfully in use by NixOS/nixpkgs here:
- <https://github.com/NixOS/nixpkgs/pull/221308>

other gnome projects already specifying gi-docgen as native dependency:
- [gtk](https://gitlab.gnome.org/GNOME/gtk/-/blob/8cf3a95d8cd5c79d941b6430f00647caa9b52eb0/docs/reference/meson.build#L4)
- [libadwaita](https://gitlab.gnome.org/GNOME/libadwaita/-/blob/fc27700ea2463c9670cd2fb264697d52cba68b89/doc/meson.build#L27)
- [libhandy](https://gitlab.gnome.org/GNOME/libhandy/-/blob/691fa96e17172a7c1605c59005ea8021cdf3d056/doc/meson.build#L18)

If not, skip the corresponding test

scan-build currently does not neem to handle g_autofree very well...

This reverts commit deb28a4d.

Mainly useful for debugging context managers

Skip tentative addresses, which otherwise lead to binding errors and
ignore addresses that are announced as deprecated.

Fixes #83

Otherwise /test/bugs/81 will fail

Fixes #82

Fixed #81