add lxqt_wallet,a secure storage system


lxqt_wallet is Qt/C++ based library for secure storage of information.It currently ships with 3 backends,an internal one,A KDE wallet based one and a GNOME's libsecret based one.

The library can hence be seen as a library that gives a single Qt based API Qt developers can use to target KDE wallet,GNOME libsecret or an internal storage system that is independent of KDE and GNOME technologies.