Changes to logout prosess and login state storing, logout bug fix
- logout process is initiated calling FacebookAuthentication::logOut()
- logged in state is now stored by FacebookAuthentication and checked
by using isLoggedIn() method
- fixed bug: user was not able to log out when network connection was
not awailable
- handler for login browser's SSL errors
- clean-up, removed LoginDialog
- [DH] src/engine/engine.cpp
- [DH] src/engine/engine.h
- [DH] src/error.h
- [DH] src/facebookservice/facebookauthentication.cpp
- [DH] src/facebookservice/facebookauthentication.h
- [DH] src/situareservice/situareservice.cpp
- [DH] src/src.pro
- [DH] src/ui/logindialog.cpp
- [DH] src/ui/logindialog.h
- [DH] src/ui/mainwindow.cpp
- [DH] src/ui/mainwindow.h