add PKGBUILD for Archlinux

[a1lu]

A first shot of a PKGBUILD for archlinux. I am not sure with the dependencies / makedependencies though.

[siavash119]

I think it also depends on some kind of ssl/tls library. I don't know if that comes w/ qt package. Can you check and I'll merge?

[siavash119]

actually as there's enough arch users wanting a pkgbuild, I'll merge now and let you guys figure it out if there's a problem.

[a1lu]

I could not set up an clean docker image so I checked the content of qt5-base:

pacman -Ql qt5-base 
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qssl_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslcertificate_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslcertificateextension_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslcipher_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslconfiguration_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslcontext_openssl_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qssldiffiehellmanparameters_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslkey_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslpresharedkeyauthenticator_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_mac_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_openssl11_symbols_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_openssl_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_openssl_symbols_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_opensslpre11_symbols_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_p.h
qt5-base /usr/include/qt/QtNetwork/5.10.0/QtNetwork/private/qsslsocket_winrt_p.h

QtGui is also included, so I think we are fine.

Do you want to upload the PKGBUILD into the AUR and maintain it?