Like JIRA services for Confluence. The ability to periodically run code within Confluence.

Initial services we'll need are JellyService (run some Jelly periodically), PopMailService (to read in POP mail boxes), FileMailService (to read mail messages off disk), FileService (to read in files and do something with them).

Services should be installed and uninstalled. This is just the 'installation' based on a class file (ie make sure it's in the classpath and record it in a list of available services).

The user can then create an instance of any available service, with a period (how often it is updated) and any particular parameters that that service has.