[Opensim-dev] Removing libsl references from IClientAPI

[Adam Frisby]

Can we remove all references to libsl packets in IClientAPI.cs? 
Admittedly there's not too many (about 5-10 by my count), but it would 
go a long way to maintaining client neutrality.

Some of them, eg EstateOwnerMessage will need a good deal further 
abstraction (so instead ot the Generic EstatePacketHandler we have 
things like EstateTerrainSettingsMessage, etc)

Regards,

Adam