File evaluation

[danilopedraza]

The system should get a file and process it as a Symstatic program.

[danilopedraza]

There are pending tasks to do:

• [x] Do not print every expression
• [x] Report errors

[danilopedraza]

This is not done. To accomplish this, I need to be more precise about the process of analyzing a Symstatic program.

[danilopedraza]

The semantic analysis step is pending, but right now this is fine.