Activiti does not resolve namespace prefixes properly

In cases where the BPMN namespace is prefixed, the parser might throw errors.

Example:

<bpmn2:conditionExpression xsi:type="bpmn2:tFormalExpression" id="FormalExpression_6">$

</bpmn2:conditionExpression>

The type is not resolved properly in this case, so Activiti does not recognize the type and will throw an parser error.

This should also be checked for attributes like signalRef, messageRef.