Review, bug fixes

Added:

• IB system fields comparison with timestamps.

Fixed:

• Syntax changes:
  • QUERY FOR removed;
  • system fields drop rules for WITHOUT SYSTEM VERSIONING;
  • no implicit versioning for CREATE ... SELECT.
• partitioning fixes;
• SYSTEM_TIME for derived revisited;
• Error messages revisited;
• minor refactorings;
• 14 bugs fixed.