[Applications][D-Bus] Emit InterfacesAdded signal when app is installed

When a object is added to the bus we send all its properties (following the
ObjectManager recommendations) re-using most of the code that was added
for implementing the GetManagedObjects() call.
[Applications][D-Bus] Emit InterfacesRemoved when app is uninstalled

Even if our clients won't use this Interfaces, it may be useful for
debbuging purposes and for completeness of our implementation of
the D-Bus ObjectManager interface.

There was the need for the PropertyExporter object to export in
which interfaces it has properties.
Merge pull request #1225 from vcgomes/xwalk-dbus

[Applications][D-Bus] Emit InterfacesAdded and InterfacesRemoved signal