state/multiwatcher: move Delta type to this package
cleanup
Update dependencies and fix intermittent test failure.
Merge pull request #1108 from davecheney/211-state-multiwatcher-delta

state/multiwatcher: move Delta type to this package

This is the first part of the post #1103 refactoring. 

This PR moves the Delta type, which was originally from `apiserver/params` to `state/multiwatcher`. The small size of this diff suggests that this is the correct place for this type.
Merge pull request #1110 from howbazaar/remove-logged-error

Update dependencies and fix intermittent test failure.

The enqueued and done time of actions are now rounded to the nearest second.
I don't think that we care about nanosecond precision for when we decided to do some action.
The logged error call sites were changed.  Some of the calls were just plain wrong and a simple logging statement was sufficient.