GabbleJingleFactory: Resolve STUN server hostname to address
GabbleJingleFactory: Resolve STUN server hostname to address

Based on code from Sjoerd Simons.

mlundblad/telepathy-gabble,community-ssu/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,jku/telepathy-gabble,community-ssu/telepathy-gabble,community-ssu/telepathy-gabble,Ziemin/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,Ziemin/telepathy-gabble