Track trivially dispatchable admits.

[kiranandcode]

Idea by @mkeoliya: In the table of results, if we still have admits remaining in the proof (i.e we don't get round to automating this part), we can also include how many of the admits can be automatically dispatched by using sauto, maybe with appropriate lemmas. This would help to provide a motivation of how the remaining goals are "trivial", and the difficult parts are handled by our tool.