FEATURE: support org-clocking in org-timeblock mode

[tebe-nigrelli]

org-timeblock supports clocking in for entries that already appear in the org-timeblock view, but people that regularly log their time tend to have most of their timestamps in the form of clocks. Currently, viewing logs is not supported.

Please add the option show-log, as a custom variable. This would easily fix the limitations in visual clarity of the org-agenda.