Version 1.1 release

Visual changes:

• Fixed info window's black overlay not covering entire screen correctly
• Tweaked upgrade screen's info buttons from "i" to "?" to make it more obvious
• Added weapon animations for each hero to make it obvious that they're attacking
• Tweaked mage hero's default projectile attack from Thunder to Iceball to make the attack obvious
• Tweaked all enemy projectile attacks from instant Ice shock to Iceball to make the attack obvious
• Added version label to the title screen

Balance changes:

• Award EXP bonuses for every 3 cleared levels instead of every 5 levels
  • Level 13 is especially brutal if you're not leveled up correctly or you're unlucky to encounter a lot of strong enemies. To make up for that, EXP bonuses are awarded more often so you can upgrade your heroes a little more before reaching the difficult stages.