message: Heavy Galleys and Cogs can be upgraded to Caravels
diff: <UnitClassUpgradeType>UNITCLASS_GALLEASS</UnitClassUpgradeType>
  <bUnitClassUpgrade>1</bUnitClassUpgrade>
  </UnitClassUpgrade>
  + <UnitClassUpgrade>
  + <UnitClassUpgradeType>UNITCLASS_CARAVEL</UnitClassUpgradeType>
  + <bUnitClassUpgrade>1</bUnitClassUpgrade>
  + </UnitClassUpgrade>
  </UnitClassUpgrades>
  <UnitAIs>
  <UnitAI>
  <bRenderBelowWater>1</bRenderBelowWater>
  <iWithdrawalProb>25</iWithdrawalProb>
  <UnitClassUpgrades>
  + <UnitClassUpgrade>
  + <UnitClassUpgradeType>UNITCLASS_CARAVEL</UnitClassUpgradeType>
  + <bUnitClassUpgrade>1</bUnitClassUpgrade>
  + </UnitClassUpgrade>
  <UnitClassUpgrade>
  <UnitClassUpgradeType>UNITCLASS_GALLEON</UnitClassUpgradeType>
  <bUnitClassUpgrade>1</bUnitClassUpgrade>
  