Changed from static to non-static getNew/getExisting list methods (in preparation for service locator).

(Rolling back changes we are not ready for quite yet).

This reverts commit 81f586eb.

Fixed some stats-related bugs and began preparing for service locator driver loading (moved logic out of constructor, eliminated static methods).

Added plugin manager for link resolver drivers; changed resolver connection class to use dependency injection and to eliminate unnecessary complexity.

All search object generation is now done through the search manager; factored out old \VuFind\Search\Options class now that it is obsolete.

Set up plugin manager for record drivers; made VuFind\Search\Solr\Results::getRecords work with search manager.

This revision temporarily breaks related record modules -- they will be fixed in the next commit.

Search results objects' getRecord() / getRecords() methods are no longer static (to allow service locator integration).

Set up record loader to use Search Manager for class name determination; added alias to account for legacy VuFind source value in database.

Refactored VuFind\Record\Loader as an instance rather than a collection of static methods (in preparation for service locator integration).

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.

Eliminated unnecessary session assignments in logsql mode; did some refactoring to make fixdatabaseAction() slightly shorter and more readable.