Adding some filtering stuff for digging for pEp messages
It now properly shoves over the email content over DBus, and the akonadi agent spins up the pEp engine and processes the stuff. Now we just have to put a bit more logic into it and also make sure it properly syncs with other pEp users.
The MIME function which generates a string from the struct still crashes, probably due to an empty string list.
Additionally achieved finally a clean inheritance from DBus::Variants through separating the Qt from the client class.
