srm: tidy up SRM CopyRequest and CopyFileRequest classes

Some very basic refactoring of code structure:
  Place braces in consistent fashion,
  Adjust white-space,
  Choose Java-conforming variable names,
  Move field members to start of class,
  Improve some method names

Patch: http://rb.dcache.org/r/6877/
Acked-by: Gerd Behrmann
Target: master