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/Credits.h

@@ -6,7 +6,9 @@
 #include <string>
 #include <JGE.h>
 #include <JLBFont.h>
+#include <time.h>
 #include "../include/Player.h"
+
 class GameApp;
 
 using namespace std;
@@ -22,6 +24,7 @@ public:
 
 class Credits{
 private:
+  time_t gameLength;
   int isDifficultyUnlocked();
   int isMomirUnlocked();
   int isEvilTwinUnlocked();