improvements and new features

1. ajax for interactive subject search
2. ajax for sets?
   > check examples in google suggest , and oclc suggest
3. relationship to dp9
4. web 2.0 support (?)
5. lucene
6. sindication of searches or alert system (?)
   > check examples in OpenSearch
7. clicklabe metadata fields in the single_page.jsp to search all documents with the same value.(?)
8. search in the result of the previous search (?)
9. generate logs suitable for statistics (?)
10. advanced search page customizable for register users (?)

refactor

1. refactor harvester code.
2. reduce JSP code to servlet (mainly admin page)
3. cleanup database schema
4. relevance ranking vs. mysql boolean fulltext search
5. refactor database code, commandline sysadmin tool for delete archive?
6. show the set name and not the set id in the advanced search.
7. show a better organization in the search by subject