Use child nameing in assignment mutator
Remove unused constants
Use childe nameing in case mutator
Use child nameing in literal range mutator
Use child nameing in literal regexp mutator
Use child nameing in literal hash mutator
Use child nameing in return mutator
Use and improve child nameing for send mutator
Improve ussage of child nameing in arguments mutator
Improve usage of child nameing in case mutator
Fix yard docs
Adjust flay score