cvars are now instanced in &cvars_all as a tracking mechanism, there is also &cvars_n...

cvars are now instanced in &cvars_all as a tracking mechanism, there is also &cvars_null if one wishes for no expansion to occur (e.g. client commands received on the server are very untrusted).

cvars now have CVAR_CLIENT and CVAR_SERVER flags, dedicated server can only see CVAR_SERVER variables whereas client can see both because it could start a server.

cvars created via VMs will have the corresponding flag set (client vm and menu vm can see both CVAR_CLIENT and CVAR_SERVER, server vm can only see CVAR_SERVER - may cause issues with singleplayer mods, we'll see).

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@12501 d7cf8633-e32d-0410-b094-e92efae38249