Examine EventMetadata frequency flag validity

[lbschanno]

EventMetadata accepts the boolean flag frequency both in its constructor, and as an argument to its various overloaded addEvent() methods. When a value of false is passed into the constructor, 'f' rows will not be written to the metadata table. When a value of false is passed into one of the addEvent() methods, the event information will not be added to the tracked frequency counts that can later be written to 'f' rows.

Given that 'f' rows should always be written, we should consider removing the option to disable writing 'f' rows, or discuss if this flag is actually intended to control whether 'tf' rows are written. The latter consideration originates from the fact that the value passed into EventMetadata's constructor ultimately comes from the configuration properties error.metadata.term.frequency.enabled and metadata.term.frequency.enabled.