fcitx 4.2.9.1, fcitx-qt5 1.0.5, kcm-fcitx 0.5.3

[Xuetian Weng]

Hi all,
This release mainly targets supporting QPlatformInputContext::locale() . Both
fcitx 4.2.9.1 and fcitx-qt5 1.0.5 need to be used in order to make it work.

There are also certain limitations when using QPlatformInputContext::locale()
with fcitx, some input method doesn't have a language (e.g. which language
does emoji belong to?), most input methods langCode doesn't have a "country"
field, but Qt will always give it a default country, which means "en" will
become "en_US" under Qt. Also not all iso639 lang codes are supported by Qt.

kcm-fcitx 0.5.3 goes back to qtreeview again to workaround a never-fixed-by-
upstream KCategorizedView. And also tries to improve language category names
displayed on UI.

Other bugfixes and features including:
1. correctly set input window position on scaled gtk3 application
2. github issue 203
3. support unicode 8.0 in unicode module
4. qt input context is not recreated correctly when fcitx restarts.

As always, downloads can be obtained from download.fcitx-im.org. BTW, it now
uses https supported by Let's Encrypt!

Regards,
Xuetian