Enable invalidating Hibernate cache to read changes from database

A possibility to invalidate Hibernate cache used in ORM on Bamboo's database would be handy to reload/re-read data directly from database after e.g. making bulk changes in plans. In case when a myriad of similar plans is maintained rather via database (updating XML_DEFINITION_DATA) than by clicking on all the possible plans in UI. Now it has to be done by restarting Bamboo, since Hibernate cache (with a rather long TTL) keeps the old definitions and the new ones from the database are visible after restart. Restarting the build server's app is very inconvenient especially when using Elastic Bamboo, since shutting down instances and starting them up again (with success!) takes a significant amount of time.

The functionality itself could be implemented either as a button e.g. "Reload DB" in Administration interface e.g. on Database Configuration tab. A more sophisticated version could show it only in case of real databases - MySQLs or PostgreSQLs, but not in case of embedded HSQL databases - as it doesn't make sense I suppose. Having it in UI would allow the verification of who can reload it (not allowing of mischievous behaviour if Bamboo server is accessible from public network).

A simplified (or just a quick-win solution) would be to allow making an HTTP request to Bamboo's UI or API to execute Hibernate cache invalidation.