Major upgrade

Added:

• jump particles
• random generation of additional landscape elements (skulls, holes in the wall, drops)
• parallax effect 
• funny loading screen, which will be supplemented in the future
• shows the number of collected lights
• shows if a scroll is collected

Fixed:

• Goblin's skill control doesn't work from the pc
• does not join the pc
• does not join more than 2 people in the game
• Goblin's lights are not showing
• wall only opens for one player