task_system and notification_queue doesn't work with move only lambda

[EugenCazacu]

When the operator() of the task_system is instantiated with a move only lambda, the notification queue tries to move the lambda into an std::function object in the dequeue of the notification_queue. std::function is by definition movable, this is turn generates a compilation error for such instantiations of the std::function.

[FelixPetriconi]

We are aware of the problem and a solutions will be probably available in the next release

[FelixPetriconi]

As far as I see, that is fixed in the meanwhile by Sean.

[fosterbrereton]

This issue has been fixed in master as of the 1.1 release.