MxVariable subclass for fsmovie setting (#147)

* LegoFullScreenMovie variable and related

* Changes after review
- Reduce scope on global strings
- Size assert for LegoGameState (based on the constructor references only)
- 1 -> TRUE for EnableFullScreenMovie

CMakeLists.txt

@@ -65,6 +65,7 @@ add_library(lego1 SHARED
   LEGO1/legoentity.cpp
   LEGO1/legoentitypresenter.cpp
   LEGO1/legoflctexturepresenter.cpp
+  LEGO1/legofullscreenmovie.cpp
   LEGO1/legogamestate.cpp
   LEGO1/legohideanimpresenter.cpp
   LEGO1/legoinputmanager.cpp