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.
Next release is 2.4.4
Add missing tests info
rework selected private group test
Fix test: TestCodeString
Fix TestString1
Fix TestPrinter1
Fix issue with the region reader
Revert portion of commit e8ef69113a258f8bb0069529ee83b7fa10ee1bd1
Fix: Some code issues found by PVS-Studio

See bug #335 at sf.net
Fix an issue in gdcm::Scanner class

do not use strcmp with a length since value may not perfectly match. This commit fixes bug #338
Properly fails when asked for bogus configuration

It should not be possible to compress 16bits data with a JPEG lossy 8bits TS
Prevent gdcm::Reader copy

Fixes bug #339