Extend gdcm::FileChangeTransferSyntax to all TS

This commit add new capabilities to gdcm::FileChangeTransferSyntax.
It is now possible to compress raw DICOM into RLE, JPEG, JPEG-LS and JPEG-2000 with minimal memory requirement.
The RLE encoder has been redesigned from scratch and merged as a separate lib for ease of re-use in 3rd party app.
Merge branch 'release'