Add osGetGridHomeURI function

Add osGetHomeURI function to the family of osGetGrid* functions. Returns the SRV_HomeURI setting from the [LoginService] configuration.

OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs

@@ -160,6 +160,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Interfaces
         string osGetGridNick();
         string osGetGridName();
         string osGetGridLoginURI();
+        string osGetGridHomeURI();
         string osGetGridCustom(string key);
 
         LSL_String osFormatString(string str, LSL_List strings);