CacheManager should only be shutdown when last endpoint is stopped

When multiple bundles contain routes with a "cache:" endpoint, if one bundle is stopped, the cache from the other bundle stops working as well.

Solution : in method doStop of class org.apache.camel.component.cache.CacheManagerFactory, remove the call to cacheManager.shutdown().

If really useful, a more elaborate reference counting mechanism could be used to stop the CacheManager when the last endpoint is being stopped

Caused by: java.lang.IllegalStateException: The CacheManager has been shut down. It can no longer be used.
	at net.sf.ehcache.CacheManager.checkStatus(CacheManager.java:1158)
	at net.sf.ehcache.CacheManager.cacheExists(CacheManager.java:1048)
	at org.apache.camel.component.cache.CacheEndpoint.initializeCache(CacheEndpoint.java:104)
	at org.apache.camel.component.cache.CacheProducer.process(CacheProducer.java:56)