Add missing dependent: :destroy.

Remove default scope overrider method Pull request #1413 has been merged. It removes the default scope and now this overriding method is not needed any more.

Move goal, ontology to AxiomSelection.

Add views for SineAxiomSelection; move ManualAxiomSelection view to a partial.

Only compute the axiom selection once Many jobs might want to compute the axiom selection, but it only needs to be done once. The Semaphore prevents multiple computation.

Add finished attribute This allows to check if an axiom selection algorithm already has finished its execution.

Let AxiomSelection have many ProofAttemptConfigurations.

Select Axioms when proving with SInE.

Make view extensible for many axiom selection methods.

Add models: [Manual]AxiomSelection There will be more subclasses of AxiomSelection each with different attributes. To avoid creating many NULL values in the database, we use multiple table inheritance with the gem 'acts_as_relation'. This gem mimicks actual class inheritance of ruby with the method `acts_as`. The migration changes the has_and_belongs_to_many association between Axioms and ProofAttemptConfigurations to be between Axioms and AxiomSelections.