Built-in function framework is in place. Had to jump through some hoops to resolve the usual #include dependency headaches.

Environments now store a link to the global env. Makes it easy to handle 2-level scope for mixins and arbitrarily nested scopes for variables.

Trying out a different comment scanning method in anticipation of implementing the comment formatting routine.

Okay, NOW correctly handling scope wrt mixins. (If a binding exists then change it, otherwise make a new one in the topmost (i.e., local) environment.)