Types for fixnum32, booleans and undefined
Representation for fixnums (32 bits signed integers).
Representation for booleans and undefined.
v00.00.03

With this version we get three more types in our machine: signed
32bits integers, booleans and undefined value.

The changes are really minimal, but this is just a small step in
preparing the machine to start handling some real computation soon.

After this, we have:
1) a representation for 32bit (fixnum) signed integers;
2) a representation for boolean values;
3) a representation for the "undefined" value.