Encoding of Attributes with value length > 64KiB with Explicit VR

[gunterze]

Encode Attributes whose known Value Representation is none of OB, OD, OF, OW, SQ, UC, UR or UT and whose value length exceeds 65534 (2^16-2) - and therefore cannot be encoded as a
16-bit unsigned integer in the Value Length Field defined for the known Value Representation - with Value Representation UN, according DICOM CP 1066 - ftp://medical.nema.org/medical/dicom/final/cp1066_ft.pdf