Add the ability to skip an exercise

[jengler]

Have to make it up later? Punishment?

[mgyucht]

As part of this, or maybe in contrast with this, you could tell flexbot not to choose you for the next hour or some time limit.

[mgyucht]

Under the current architecture, you can skip exercises by simply not doing them, and they just don't get logged. That may or may not be good enough, depends on what exactly you're thinking about this.