Beginnings of the "pass everything using a native type wrapper" console code.

- ConsoleValue class is now the base value class.
- ConsoleValueRef is now used to supply function parameters. Values are disposable.
- Script functions return values instead of just strings where possible.
- Variables can be disposable strings
- Bytecode changed

Fix the issues with console method parameters and fields which prevented missions from loading.

Engine/source/gui/controls/guiMaterialCtrl.cpp

@@ -169,5 +169,5 @@ void GuiMaterialCtrl::onRender( Point2I offset, const RectI &updateRect )
 ConsoleMethod( GuiMaterialCtrl, setMaterial, bool, 3, 3, "( string materialName )"
                "Set the material to be displayed in the control." )
 {
-   return object->setMaterial( argv[2] );
+   return object->setMaterial( (const char*)argv[2] );
 }

Engine/source/gui/controls/guiTreeViewCtrl.cpp

@@ -4928,7 +4928,7 @@ ConsoleMethod( GuiTreeViewCtrl, setItemTooltip, void, 4, 4, "( int id, string te
       return;
    }
    
-   item->mTooltip = argv[ 3 ];
+   item->mTooltip = (String)argv[ 3 ];
 }
 
 ConsoleMethod( GuiTreeViewCtrl, setItemImages, void, 5, 5, "( int id, int normalImage, int expandedImage ) - Sets the normal and expanded images to show for the given item." )