Two inter-related changes:

1. fixed bug where Search Manager would load incorrect objects because state had been changed in between calls (i.e. $params object may use Search Manager, changing its state before $results object can be created -- to avoid, we need more explicit calls to setSearchClassId())

2. refactored record drivers in preparation for plugin manager (moved constructor parameter to setRawData method).  This allowed more common functionality to be moved to the abstract base class.  Renamed getAllFields() to getRawData() for consistency.

Small bonus change: turned off highlighting/spellchecking/recommendations in BrowseController for improved performance.