Modular approach for Pioneers and Colonists

Refactored CvPlayer::foundMid() and CvPlayer::foundLate() into one paraterised CvPlayer::cityBoost() method

There are a couple of TODO's related to this change in CvUnit::found() - to further parameterise the calls

kPlayer.cityBoost(getX(), getY(), m_pUnitInfo, GC.getPIONEER_EXTRA_PLOTS(), GC.getPIONEER_POPULATION_CHANGE(), GC.getPIONEER_FOOD_PERCENT());
kPlayer.cityBoost(getX(), getY(), m_pUnitInfo, GC.getCOLONIST_EXTRA_PLOTS(), GC.getCOLONIST_POPULATION_CHANGE(), GC.getCOLONIST_FOOD_PERCENT());

but this needs the corresponding entries in the Defines table and CvGlobals