Create a system that allows the player to save and continue the game at any point, save & quit at any point, and load a saved game from the main menu

[anthonyLuttrell]

• The player will have an in-game menu that they can save from at any point in the game
• The player should also be able to choose to save & quit the game from the same menu
• From the main menu, the player can choose to load a previously saved game from at least one save slot
  • Add more save slots if you want
• On the main menu, the game save should give the player a time stamp, along with just a few basic game stats, like colony population, the number of remaining rival colonies, etc.

https://github.com/warofants/wwa/wiki/Save-&-Load