Daddy32: Tasks Mode

Gives the user the opportunity to earn some credits for performing various tasks.

Known bugs removed, tested stability-wise, not so much game-wise.
Lots of to-dos and ideas still remaining, better balance between task difficulty and their rewards needed - please comment.

Usage:
Enter shop, open menu, select 'See available tasks'.
All tasks in the list are active, until they expire ('Days left'; day passes after each duel (won, lost or quited)).
You can finish any of the tasks and get bonus. For particular task, the bonus gets a bit smaller every day (until expiration).

projects/mtg/include/GameObserver.h

@@ -11,6 +11,7 @@
 #include "ReplacementEffects.h"
 #include "GuiStatic.h"
 #include <queue>
+#include <time.h>
 
 class MTGGamePhase;
 class MTGAbility;
@@ -46,6 +47,7 @@ class GameObserver{
   ReplacementEffects *replacementEffects;
   Player * gameOver;
   Player * players[2]; //created outside
+  time_t startedAt;
 
   TargetChooser * getCurrentTargetChooser();
   void stackObjectClicked(Interruptible * action);