Typo fix
Ensure property keys are always strings
Refactor Rip::Core::Lambda (and associated chain of objects) to use Rip::Nodes::Parameters for parameters

Also refactor Rip::Core::Lambda#call to stop requiring the calling context and to accept pre-interpreted arguments
Refactor Rip::Core::Base#[] to bind `self` to `reply.@` when `reply` is a lambda

Implement Rip::Core::Lambda#bind and System.Lambda.@.bind
Properly bind `@` to lambdas when lambda is retrieved as a property [T #9]