Improve cache abstraction chapter

This commit is a general update of the Cache Abstraction chapter.

Existing sections have been updated with recent improvements made in
that area, in particular:
* Guava and JSR-107 caches support
* New @cAcHecONFig annotation allowing to share some key customizations
  at class-level
* CacheResolver interface used to resolve the cache(s) to use at
  runtime
* Update section on @cACHEpUT

This commit also describes the support of standard JCache annotations,
i.e. JSR-107.

Issues: SPR-11490, SPR-11316, SPR-10629, SPR-9616, SPR-8696

Author: snicoll