Use JCache (JSR-107)

Putting it in jira since it's a valid question but since the JSR-107 hasn't released any specs for years I don't know if that would be the right move.

Note: I created this issue when I seen that the new JBossCache 4 (now called Infinispan) added support for JCache.

Reference API available on http://search.maven.org/#search|gav|1|g%3A%22javax.cache%22%20AND%20a%3A%22cache-api%22 and https://github.com/jsr107

Current status on https://github.com/xwiki/xwiki-platform/tree/feature-jcache.