Tasks and jobs need more verbose output

[chillu]

• Jobs should declare which class they're acting on
• ReindexJob should declare how many records need to be reindexed, and how many jobs it has created for which indexed classes. Same with ClearIndexJob
• Configure should declare whether a schema change was required (ideally which fields were added)
• IndexJob should have some output when running (currently a ProcessJobQueueTask CLI exec just looks like it's broken for longer tasks)
• All tasks should have a "verbose mode" which logs the API calls and payloads made to the underlying service

Sorry, could've fixed these myself but the module is currently a bit in flux according to Aaron (local commits), so I'm being lazy and writing it down here instead ;)