update defaultPolicy dict

def policyChange(self, updateParams, func):
		""" update defaultPolicy dict """
		for k,v in updateParams.items():
			k = k.replace('-','_')
			c = globals()[k](v)
			try:
				self.defaultPolicies[k] = getattr(c,func)(self.defaultPolicies[k])
			except Exception, e:
				raise