Normalizes Tableaux.hs to support State monad
WIP (NW): State monad in action ...such a mess :P

NOT Working
WIP (NW): Everything is under State Monad

* Most of the tests are not working
State Monad is working now

* Needs more testing
* Needs further refactoring (a lot of it)
WIP (W): Refactoring in action
Source Refactoring

 * Define: type TableauxState = State ModelState
 * Define: type IndPair = (Individual, Individual)
Some changes to the algorithm

We need to take special care while adding new individuals in the
frontier.
addIndividual change in order some assertions to be added at the end of
the frontier
More refactoring and some 'minor' changes

 * Minor change: findRoleFiller. Now if the concept is T (Top Concept)
 * it is not taken into account
Renaming: DLReasoner.hs -> ReasonerADT.hs

 * Some more renamin/refactoring