Woah!  Got carried away with const.  This commit Removes the const
qualifier from the ArchiveFileItor::next() method because next()
modifies the iterator.

To loop through an ArchiveFileItor:

  auto itor = catalogue.getArchiveFilesForRepackItor(vid, startFSeq);
  while(itor.hasMore()) {
    const auto archiveFile = itor.next();
    // Do something with archiveFile
  }

Also organised common in subdirectories, and added sub directory for mockDB.

Added the unique pointer for sqlite statements with custom deleter and fixed the error reporting for SQLite prepare

License comment is no longer filtered out by doxygen when generating web pages of the individual source files.

Created AdminUsersList in the object store as a first step to implement an object store middle tier.
Some namespace fixes for unit tests.

Implemented the new interface on the Rados backend.
Fixed several bugs.