Open Question Panel property conversion.

Added helper methods to TriviaPanel for setting TextArea
properties.

Fixed border issue with scrollable text areas.

Converted Open Question Panel constants to properties.
Answer Queue Panel property conversion.

Converted constants in AnswerQueuePanel to properties.
Round Question Panel property conversion.

Converted constants in RoundQuestionPanel to properties.
History Panel property conversion.

Converted constants in HistoryPanel to properties.