[#LIB-195] Refactor SAXWriter
[#LIB-192] Provide JSONReader to read Data Set from JSON presentation
[#LIB-196] Provide JSONWriter to write JSON presentation of Attributes
[#LIB-197] provide utility dcm2json to convert DICOM file to JSON
Merge branch 'master' of github.com:dcm4che/dcm4che