Add task and lastActivity info to task summary

This adds last activity time, total tasks and completed tasks to the summary allowing better history information to be shown.

'V2' has been removed from a few places and some unused transition code has been removed. Casbah has also been removed as it is no longer used. Ununsed imports cleaned up. String interpolation introduced.
I lied about casbah
I lied about casbah
Kill off tests from V1
Migrate more tests, classes, methods and logging away from Deploy V2
Merge pull request #160 from guardian/sh-task-summary

Add task and lastActivity info to task summary
Merge branch 'master' into sh-cross-charge
More charging code