Add support for moving multiple users/channels#1871

Draft

austinliou wants to merge 4 commits intomumble-voip:masterfrom austinliou:multidrag

+174-132

Commits on Nov 1, 2015

Add support for moving multiple users/channels
austinliou
committed

Commits on Nov 2, 2015

Ignore channel movement with multiselection
austinliou
committed

Commits on Nov 20, 2015

UserModel: Treat QByteArray::size() as unsigned
austinliou
committed

Commits on Nov 29, 2015

Force channels to deselect in multiselection
austinliou
committed