Bug fix for the write_line() function.
Added a missing RelaxError import.
Fixes for the sequence.write() user function arg unit tests.
More fixes for the sequence.display() user function arg unit tests.
Fixes for all the sequence.display() user function arg unit tests.
Updated the sequence.write() user function.
Updated the sequence.display() user function.
Updated the display() function.
Changed all the '*_flag' arg default values from True to False.