Reset enabled properties of back and next buttons, according
to whether the current message is the beginning or the end
of the discussion message Vector.
Updates the global stylesheet by removing how inline annotations should be rendered;
Also removes any style information associated with links, so that we can change the styling based
on user preferences
Takes a String and executes it as an SQL update query
Identical to query( String ) but does not return a ResultSet
All queries should use query( String ) or updateQuery( String ) to enable
offline (local) database access.