A new transform has been created, its goal is to collect informations
about all statements dependencies in order to use it to decide which
statements can be ignored.

The `Dependencies` transform for now collect all this informations:
 - Global Variables
 - Variables interdependencies
 - Function details (Parameters, Variables used, Number of statements)

Two debug functions have been added for a better understanding, the
first one prints all informations. The second output a GraphViz graph,
so we can visualize `variables` interdependencies and their respectives
scopes.

 * main.go : Modified.
   transform/dependencies.go : Here.