- Add testcase for the new error message
- Add testcase for starting cluster with InitialLogFileGroup with undo_buffer_size greater than
 available  SharedGlobalMemory. Check that memory was allocated for undo buffer
  and that the created log file group is usable.
 - Slight change of error message to indicate that user can choose between reducing the undo_buffer_size
   or increase SharedGlobalMemory
 - Slight change of logic in the code which (pre)allocates the memory to only peek at
   the undo_buffer_size value in the InitialLogFileGroup spec. This avoids duplicating all the logic from
  NdbCntrMain.cpp and should make the behaviour more distinct.