#82-am Enhance the functionality of onix gem.
#82-am Move reference files used to onix parser gem

- Change xsltpath to point onix support xls file
- Change JAVA_JAR_FILE to point onix java jar file
#82 Update SCHEMA_LOCATION path in writer.rb
#82 Modify Java jar file path, xsltpath
#82 Change SCHEMA_LOCATION file path
#82 Add comments

- change schema path
#82 Add comment on xsltproc