GUI Updates

[GAIGResearch]

• [x] close button: to close the GUI allowing the game to close naturally
• [x] water unit should show their base land unit
• [x] currentHP/maxHP over all unit sprites
• [x] Differentiate in the GUI if a tech is not researchable just because not enough stars
• [x] Make it visible when playing with agents
  • [x] Attacks: we need to show that it actually happens.
  • [x] Same for Convert and HealOthers
• [x] History of actions (Action.toString()) in a new tab, with headings for tribe and turn
• [x] On Game End, GUI to be responsive.

[rdgain]

And more:

• [x] Sprite updates: roads tiling correctly
• [x] Pause/Resume functionality
• [x] 'Play Turn' button with automatic pause afterwards (either per player, or all tribes)
• [ ] Move all functionality to the GUI:
  • [ ] game seed, level seed
  • [ ] choose map,
    • [ ] edit map
  • [ ] choose players, random seeds, tribe per player
  • [ ] visuals on/off
  • [ ] start/restart/end game
  • [ ] results printout for all games in the same run (if multiple)
• [ ] Debug functionality in GUI
  • [x] observability toggle
  • [x] save game toggle
  • [x] add comments to saved game files
  • [ ] change game configuration?
• [x] GUI should ignore action display for non-human players?
• [x] Human competitive mode: player can't see information of other units (i.e. when clicking on them) unless it's their turn
• [ ] GUI toggle through tribes views (for pause modes)
• [ ] Rewind&Replay functionality
• [ ] Tech tree search functionality (i.e. "custom house -> Trade research")
• [ ] Action history search functionality