Hotfix #15

Hi! Some fixes for out last update:

• Fixed Emperors gifts history not displaying correctly;
• Fixed rivers tiles not drawing correctly in constructor mode;
• Fixed 'set position in the center of the screen' for dialogs and messages;
• Fixed crashing when you use plateau tiles in constuctor mode;
• Fixed "undo last action" for farms;
• Fixed a glitch when a wrong cost was displayed when destroing buildings;

• Improved economy issues history window;
• "Scribes messages" button is now highlihted when a city has new messages;
• Improved paths rendering on information layers.

See you soon! Cheers.