[BACKLOG-174] - The command line import utility in 5.0.0 is over three times slower than 4.4.0 GA.
- Database
  - amount of separate queries objects to database is reduced by using batch mode
- RepositoryExportSaxParser
  - uses the only builder during export
- RepositoryImporter
  - get several small speed-ups
  - holds the only DocumentBuilder for creating DOM-documents instead of
    re-instantiating it each time
- XMLHandler
  - now obtains external builders
  - 'final' modifiers of static methods are removed as they are
    meaningless
- Import
  - improve readablitily a bit
Merge pull request #667 from akhayrutdinov/BACKLOG-174

Backlog 174 - The command line import utility in 5.0.0 is over three times slower than 4.4.0 GA.