Add the ExpresionRegular class.

The ExpresionRegular class represents a regular expression.
Add the generator of validator.

The generator creates a .java file that has the source code of a validator of a
regular expression.
Add the generator of the image.

The generator creates a image of a DFA.
Add the GUI of the program.

The Ventana class is responsible of the GUI.
Solve a runtime exception.

Before adding the initial state of the transition table is initialized the
transition table.
Improve the documentation.

Adds the javadoc to Alfabeto#hasSimbolo.
Add a TODO.

Adds a TODO to EstadoAFD#equals.
Add a validation for the TablaTransicion#actualizar.

Verifies that the new next state is not already in the set of states
following.
Change in the main class.

To launch the program is created the GUI.