namebox 0.1.9

Create namespace boxes to protect the core classes' methods from changes, like refinements. Note: this is the last version compatible with Ruby 1.8.7 and 1.9.1. It's slow, memory-consuming and it has some issues about loosing 'self' when in class methods changed by extending modules in subclasses (self will be the class instead of subclass when namebox is closed). Next versions will be only compatible with Ruby 1.9.2 or greater.