use EstablishContextException() and ReleaseContextException() classes instead of "raise string" which is now unsupported by Python 2.6
use EstablishContextException() and ReleaseContextException() classes
instead of "raise string" which is now unsupported by Python 2.6

LudovicRousseau/pyscard,LudovicRousseau/pyscard,moreati/pyscard,LudovicRousseau/pyscard,moreati/pyscard,moreati/pyscard