kmsirtpconnection: add "added" property
kmsirtpconnection: add "added" property

Change-Id: Iac481a46585c9d9a30e2d3ff92a2ac6be3f241b9

Kurento/kms-core,shelsonjava/kms-core,ESTOS/kms-core,shelsonjava/kms-core,shelsonjava/kms-core,Kurento/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,ESTOS/kms-core,TribeMedia/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,TribeMedia/kms-core,TribeMedia/kms-core,ESTOS/kms-core