Ability to add something done today that's not a Pomodoro (for the report)

[dracan]

Quite often in the day, we have things like meetings and things that don't really work as Pomodoros.
When you view the report, it would be nice to be able to see that you've done those too.

Create a right-click menu item called "Add Supplemental Activity".
This should open a dialogbox where the user can enter free text.
This isn't tied to a pomodoro, but it tied to the current day.
It should be persisted.
The report should include this in the today view and also the expanded "Daily History" sections.

[dracan]

0297ba3