Turned the abstract graph classes into generics

It will need more work to be fully coherent.
Added GraphFactory that will create a full graph from only transitions.
Finished the Generic type for the abstract graph files

The result may seem completly repulsive. However, I don't know if there
is a more elegant solution. Will look for it.
GraphFactory finished except for the Event, Condition and Actions fields

- Implementing the functions addState and getState in StateMachine
- Turned the states id into String
Changing the name from Event to SingleEvent
Adding the functions for parsing the events and the conditions in
GraphFactory.
Changing names :
-addEvents to add in action
-getState to retrieveState in GraphFactory
Adding new class CommandEvent
Models are now printable (toString() overridden)
Implementing a function to write the file from the states machines.
Implementing an iterator function for the Events.
[AEFD specific]Added a parsing to identify all the ACT internal messages

The AEFD format is the format currently used in the company where this
sofwtare is developped. There is nothing interresting about it, it is
simply internal business.

- Added this function in GraphFactoryAEFD
- Added more documentation into GraphFactoryAEFD
- Created an implementation for Condition. It is the simplest thing
possible that simply stores the String in order to be able to compare
the file to be loaded and the actual loaded model.

TODO : there still need to order the transitions
Bug fixes

Bug corrected in b46353 were re-introduced in 951045.
Checking integrity when loading an AEFD file

When loading an AEFD file, we print out a new file from the extracted
data and we compare the new result with the initial one.

From now, we does not strictly write the model, but only the transitions
that should have been added into the model.
For a strict verification, we should also check that transitions added
to the model are correctly added.
Integrity checking when loading an AEFD file is now complete.
[AEDF specific] P_? are now considered as commands
Remove the space before (Action Condition and Evenement) when they have
an empty field.
Formula and convertion to conjunctive normal form (CNF)

TODO: JUnits test to test the transformation.
Integrated the ANTLR boolean expression parser
Bug fixed

[a-zA-Z|0-9]+ replaced with [a-z|0-9]+.
Completed the grammar

- It now accepts A-Z and _ in identifiers
- Created the backbone of the parsing of formula within Formula.java
Further developement on formulas

- ToString added
- Converted Variable and Literal into Formula
- Corrected an invalid constructor
Updated .gitignore and added the Eclipse configuration files