refactored Timer

changed Timer to be added as a component instead of being created as an
individual game object
refactored GUI

added GameStateManager classes from which the GUI classes take the
information to draw. The GUI classes now don't listen to events, but
retrieve the information from the GameState classes
refactored Player

added events PlayerActionSuccess and PlayerActionFail for listeners to
better distinguish and avoid if statements in the listening method
renamed Player events and added gameStateManager
added GUI depth and fixed credits icon location
added GUI depth to actions
refactored ActionsGUI

changed name to ActionIconsGUI and put the Action logic in the
ActionInvoker
also added an virtual IsPerformable method to the Action class and
changed the return type of Perform to void
fixed ActionInvoker

The ActionInvoker now again only gets called once for each action
Switched negative and positive selection buttons of player 2 since there
was a bug after doing the fixing
refactored Disasters

split the ActionEntity (e.g. Tornado, Thunderstorm) and the Action (e.g.
spawning a Tornado, Thunderstorm) itself
added Actions for Instatiating ActionEntities
added Layers class for the different layer masks
added component for spherical movement
refactored disasters

cleaned up disasters, removed unnecessary variables etc.
changed some data on actions/entities
saved scene and fixed indentation
refactored planet and placing system

split placing system in BuildSlots, BuildingPlacer and TreePlacer
Also added PollutionScreenFader for the pollution overlay
rearranged directory structure
removed unnecessary standard assets
saved project file
fixed some bugs

fixed CameraMovement, mountain size, lightning/thunderstorm
added hitpointLevels to building
fixed tree size