Bump the version number to 0.8.3.
Bump the version number to 0.8.3.

Changes since 0.8.2:
- Use GB18030-2000 instead of GB18030-2005.
- Add read/write support for overlay data.
- Add read support for uncompressed YBR_FULL_422.
- Update the dictionary for DICOM 2017c.

Bug fixes since 0.8.2:
- Fix some incorrect ISO 2022 enum constants in header.
- Fix decoding of 4-byte  GB18030 codes.
- Fix Set/Get of DS values for locales with ',' as decimal point
- Fix invalid PatientMatrix for MemoryRowOrder=BottomUp.
- Use correct VOI LUT Function in vtkDICOMApplyPalette.
- Fix data-set generation for multi-stack source data.

dgobbi/vtk-dicom,dgobbi/vtk-dicom,dgobbi/vtk-dicom