strict mode for assessor.js
Add "And" verifier and fix the Or verifier
Bugfix Verifier.Or.toJSON()
Add new verifier Point and experiments with the And/Or verifiers.
Refactored practice for better maintenance

The verifiers are now split into separate, smaller files.
Refactor values.js, add new value "Sum"
Move the not Verifier from compare to logic
Use ids instead of names to compress the fixtures list
New verifier 'Score' that always returns true but stores the value in the score
New value 'Div', calculating the quotient of two values
Fix div value
Bugfix div value
Fix Score verifier
Fix GEQ verifier
Merge branch 'master' into refactor
Move some general purpose verifiers over from GUI