BUG FIX: Switched to BigDecimal for channel comparison.  Double gave
rounding errors e.g. 1234.56 => 1234.560001 which then caused comparison
problems.
Added: Person(int, String, String, Connection): Creates a person object
by looking up the record in the person table
Added: populateConversationHistory(Connection): Reads the conversation
associated with this person record
+ JavaDoc spelling error
Stored language/country for when we create Person objects in the CHANGED
command
Implemented CHANGED command
Added notes to clarify why we would have 0 answerListeners
Skeleton for changeActivePerson TODO