Add Store and Upgrade Items

• Add new Store where we can buy items to improve Strenght and Speed of the ship.
• We can earn MCs credits (coin of the game) finishing levels or buying it at the store (For android purposes).
• We can use the bought upgrades  at the See Ships Menu .
• Also we have changed the bottons of the GUI
• Added new system of life using colours

Fixed issues

• Loading screen for level 3 is now OK
• When we finish level 3 Level 4 is now unlocked correctly