Minor fix and change with score icons for morphed player classes
Firstly, this fixes a bug where a morphed player class's score icon wasn't being replaced by that of the player's original class in online games. More specifically, this line in P_MorphPlayer
wasn't replicated in ServerCommands::SpawnPlayer::Execute
: morphed->ScoreIcon = actor->ScoreIcon; // [GRB]
Secondly, this extends the behaviour of the NOMORPHLIMITATIONS
actor flag by not replacing the morphed class's score icon with the original's, if the flag is enabled.