Bluez5: QBluetoothLocalDevice becomes invalid if adapter disappears

Bluez5 supports org.freedesktop.DBus.ObjectManager interface which
permits monitoring of removal/addition of Bt adapters. This permits
the invalidation of the current QBluetoothLocalDevice instance. Once the
instance is invalid, it will remain invalid. Otherwise we could have a
switch of the adapter without the developer noticing it because the next
Bt dongle could get the same interface path. This would
violate the sense of identity that is attached to a
QBluetoothLocalDevice instance.

Task-number: QTBUG-38399
Change-Id: I007278ff1f94c48d6e6902959132088858b0d011
Reviewed-by: Aaron McCarthy <mccarthy.aaron@gmail.com>
Don't stop processing of Bluez services if one service is invalid

This is a regression introduced during the Bluez5 port. During the
service xml parsing we may encounter an invalid service info. This does
not mean the next one is invalid too. This bug caused the service
discovery to abort.

Change-Id: If51e0f898d83e99ba0a279c13ccaa3e5947bb6bf
Reviewed-by: Aaron McCarthy <mccarthy.aaron@gmail.com>