correct bug - fix argument name
Add and export utility functions for changing of prototype and remove slots: change-prototype, remove-direct-slot, clear-direct-slots. Add feature - prohibition of walk through slots of prototypes, for this variable's *walk-prototype* is set to NIL. Correcting using find-slots (for Lispworks) into methods: slot-boundp-using-class, slot-makunbound-using-class. Update tests
Merge pull request #3 from LinkFly/master

correct bug - fix argument name