Improving "cancelActivity" attribute handling with JsonConverterUtil.getPropertyValueAsBoolean(name, objectNode, defaultValue)

Based in Activiti Designer, I added the process attributes in the Pool object and stencilset. This means that the pool attributes, such as ProcessRef, Name and Executable, will be used to compose the Process object.

- Added 'form values' (id, name) to form properties
- Added 'required', 'readable' and 'writeable' to form properties

Json converter not read process documentation from model node while creating bpmn object. Therefore there was no description in process definition after deploying model