Update on AVATAR simulator: blocks can now be undisplayed on interactive simulation

src/android/readme

...tartranslator/directsimulation/AvatarSimulationBlock.java

...lator/directsimulation/AvatarSpecificationSimulation.java

...ractivesimulation/AvatarInteractiveSimulationActions.java

...vatarinteractivesimulation/AvatarMainCommandsToolBar.java

...ctivesimulation/AvatarSpecificationSimulationSDPanel.java

...eractivesimulation/JFrameAvatarInteractiveSimulation.java