Add cache abstraction tests using JSR-107

This commit adds an extra test implementation that runs the cache
abstraction tests using a JSR-107 cache manager. This further covers
JCacheCacheManager.

The actual JSR-107 implementation is ehcache-jcache that requires at
least ehcache 2.8.3. Since the ehcache-core artifact is no longer a
public artifact, this commit switches to the full ehcache library,
that is net.sf.ehcache:ehcache
Remove unnecessary warning suppression in ModelResultMatchers