bug fixed for ehcache. The operation of the cache-diskstore pair seems not operate in a correct way when retrieving a big object composed of many data. When a big object is retrieved, some data, previously stored, have been corrupted.
In order to solve the problem, a safe procedure has been implemented that, once recovered the data from cache, checks if the data are corrupt. If yes, they need to be recovered again
git-svn-id: https://svn.d4science.research-infrastructures.eu/gcube/trunk/portlets/user/databases-manager-portlet@101672 82a268e6-3cf1-43bd-a215-b396298e98cf