Some cleanup for deserialization.
Merge branch 'multiplayer' of git@github.com:MovingBlocks/Terasology.git into multiplayer
Fixed an issue causing saved games to fail to load due to their reliance on the engine mod.
Fixed UIDialogModules/UIDialogCreateNewWorld not interacting correctly, so the selections made in UIDialogModules were ignored.
Added a new module, 'malicious', for testing module sandboxing.
Added @API annotation to mark engine interfaces and classes that modules may use.
Expanded on the module security manager and added a module class loader to enforce allowed access (disabled in this commit, pending setting up the whitelist).