android-daemon: Only react to network changes if wifi is connected
android-daemon: Add advanced endpoint ID selection

With this patch the user can choose between DTN or IPN scheme. The endpoint ID is
then calculated using the android ID. Additional the user can choose a custom
endpoint ID.
android-daemon: Remove security preferences for timestamp / lifetime limitations
daemon: Remove unnecessary includes
ibrdtn: Convert MD5 chars into host-byte-order before using them as IPN hashed number
android-daemon: First shutdown session manager, then restart the daemon process