cleanups: WorldObjectsContainer, WorldObject. closes #40
PhaseHeroes.java revert to master
rename: TerrainObjectsMaster->TerrainMaster
code cleanups
name change. Interaction -> Collision
little cleanups
cleanups one more time
WorldObjectsContainer-->WorldObjectsMaster, RenderableObjectsContainer-->RenderableObjectsMaster
cleanups
preparations: getting rid off getWorldType(), getEntityType(), getItemType
new WorldObjectType
Tile::occupants refactor first steps
refactor logic fixes
Nullable.java
WorldObjectVisitor
refactor's next stage: preparation for new collision result resolving (Visitor pattern)
CollisionsMaster -> Singleton pattern
CollisionsMaster->CollisionsMasterBeforeRefactor
new CollisionsMaster and its helper classes
EnemyCollisionVisitorEnter.java EnemyCollisionVisitorStop.java