Add more information about the CacheStore API to the dev guide.
This feature is to change considerably for 6.2. Waiting on development before any docs updates.
*** Bug 1004560 has been marked as a duplicate of this bug. ***
The Cache Store API has been replaced with a Persistence SPI. Closing this bug as a duplicate of BZ#1014420. *** This bug has been marked as a duplicate of bug 1014420 ***