Resolve "Calibration task should accept "detector_config""

Closes #21 (closed)

PyFAI has a lot of configuration parameters which are all in integration_options. Ewoksxrpd extracts those parameters that are not just for integration (e.g. calibration or diagnostics need them as well). These parameters are "detector, "wavelength", "dist", "poni1", ... In this MR we extract another one called detector_config.

This means in all tasks that need the detector object we can do

detector_object = pyFAI.detectors.detector_factory(detector, config=detector_config)

while before we only had support for

detector_object = pyFAI.detectors.detector_factory(detector)