Fcitx 4.2.9.5 and other libraries.

[Weng Xuetian]

Hi All,
This release is mainly focused on Qt 5 related stuff, and compatibility with
Fcitx 5 and flatpak.

In this release, all qt gui plugin, including ones in fcitx-{skk,kkc,unikey}
are ported to Qt 5. In order to avoid cyclic dependency, Quickphrase plugin is
also moved to fcitx-qt5.

Also, if one can include fcitx's im module in flatpak runtime, they will be
able to use fcitx in the flatpak. Also, because of this change, I intentionally
make this portal interface using the dbus interface from fcitx 5. As a side
effect, it enables your to use any combinition of fcitx server and fcitx im
module together. This will make user future migration to fcitx 5 easier. I'm
also working with flatpak upstream to make the runtime include fcitx's plugin
so it will work for everyone out of box.

Another important change is that, the platforminputcontext plugin is now re-
licensed to 3-Clause BSD, and an additional option is added to make fcitx-qt5
only build the plugin. This make it easier for application that need to bundle
Qt library to include fcitx plugin.

Regards,
Xuetian