Issue446PrivateFieldsPhilipsAlluraXper

Refs #446 Get data from private fields for Philips Allura Xper

Import:

• Use Philips private shutter positions to calculate collimated field parameters if not available.

• Remark: due to the fact that we don't check for the Coding Scheme Designator, we get the privately defined "Table Height Position" for Philips Xper data instead of the DICOM defined one. It seems they are defined the same.

Calculating skin-map:

• If end angle for rotational acquisition is not defined and the start Angle is -120 assume a Philips XPer propeller mode scan.

• If end angle for rotational acquisition is not defined and the start Angle is -45 assume a Philips XPer roll mode scan.

• Remark: calculating a skin-map still won't work due to other geometrical issues.