tedivm/Stash — pull request #26 by jhallbachner (2012-02-28 21:19:27+00:00)
Title: isAvailable/canEnable and Sqlite Subhandler Selection

* Separates isAvailable() (can this handler be used in any context) from canEnable() (is this specific cache instance usable)
* Checks whether the handler instance can be enabled before calls to store() and get()
* Ensures that all handlers can be instantiated without throwing an Exception
* Causes Sqlite handler to step through subhandlers in preferential order if none is specified, rather than dying if the most-preferred option is not available
* Reconfigures StashHandlers::getHandlers() to return a list of Handlers which are available, rather than all those which exist