cardHolder_center added

trying to do verifyPoligonCollition
cardHolder_center now works with polygons

verifyPoligonCollition is now working
verifyRectCollition and verifyCircleCollition added

NOT TESTED
cardHolder_center add child function

is not yet working, but it's close
Merge pull request #17 from gastonci/gastonci_work

Gastonci work merge