dcm4che utilities : Fix issues and improve documentation for several dcm4che tools

[vrindanayak]

• Fix incorrectly displayed help information (-h) on using version flag (-V) for tools :
  • fixlo2un
  • json2props
  • json2rst
  • planarconfig
• Fix try --help not shown if there are errors running a tool for :
  • json2index
  • json2props
  • planarconfig
• Add missing README links on dcm4che Utilities usage overview for :
  • fixlo2un
  • json2dcm
  • json2index
  • planarconfig
  • tpl2xml
• Improve --help description with examples for :
  • fixlo2un
  • json2index
  • json2props
  • json2rst
• Add README for json2index - Currently leads to 404 - Not Found
• Fix failures on using json2index tool :
  • NullPointerException thrown on using -h

    Exception in thread "main" java.lang.NullPointerException
          at org.dcm4che3.tool.json2index.Json2Index.process(Json2Index.java:75)
          at org.dcm4che3.tool.json2index.Json2Index.main(Json2Index.java:68)
          Suppressed: javax.json.stream.JsonGenerationException: Generating incomplete JSON
                  at org.glassfish.json.JsonGeneratorImpl.close(JsonGeneratorImpl.java:511)
                  at org.dcm4che3.tool.json2index.Json2Index.process(Json2Index.java:72)
                  ... 1 more
    

  • FileNotFoundException thrown if <schema-dir> contains sub-directories

    java.io.FileNotFoundException: /home/vrinda/Desktop/test/mr (Is a directory)
        at java.base/java.io.FileInputStream.open0(Native Method)
        at java.base/java.io.FileInputStream.open(FileInputStream.java:213)
        at java.base/java.io.FileInputStream.<init>(FileInputStream.java:155)
        at org.dcm4che3.tool.json2index.Json2Index.processFile(Json2Index.java:125)
        at org.dcm4che3.tool.json2index.Json2Index.process(Json2Index.java:104)
        at org.dcm4che3.tool.json2index.Json2Index.main(Json2Index.java:86)
        Suppressed: javax.json.stream.JsonGenerationException: Generating incomplete JSON
                at org.glassfish.json.JsonGeneratorImpl.close(JsonGeneratorImpl.java:511)
                at org.dcm4che3.tool.json2index.Json2Index.process(Json2Index.java:99)
                ... 1 more
    

• Fix NullPointerException thrown on json2props if a file is specified instead of <schema-dir>

  Exception in thread "main" java.lang.NullPointerException
        at org.dcm4che3.tool.json2props.Json2Props.json2props(Json2Props.java:91)
        at org.dcm4che3.tool.json2props.Json2Props.main(Json2Props.java:76)