Initializing test harness and build system.
Value representation of pointers.
v00.00.01

The virtual machine is nowhere near a "machine" yet. It recognizes
one type of value (pointers, implemented through the value_t
data type) and is capable of running "programs" that consist solely
of returning a constant value stored in the program.

No virtual machine operations are supported so far, and programs
(implemented through the module_t data type) are simply a
structure wrapping a single register of type value_t, which
represents the value it will return.

This version is absolutely useless, but gives us the following basic
entities that are needed for future improvement:

1) A representation for values, so far limited to pointers, but this
   is easy to extended to other values, as we'll see in a couple
   versions ahead;

2) A basic representation for our evaluator, which starts to define
   the interface client code can use to manipulate it;

3) A simple representation for modules which can be used to
   represent our programs (each program is a package of one or more
   modules).

4) A nice infra-structure to perform tests on what we have so far.