Version 0.12.5

Some bug fixes and License update.

• Updated the License to EPL-v2.0
• Added some missing Eclipse Paho legal documents.
• Added TopicMatcher::insert_many()
• #216 Deref QoS pointers for SubscribeMany and UnsubscribeMany in server response
• #215 Now subscribe_many() returns an error if slices not the same length. Also added subscribe_many_same_qos() to the clients.