Fourth day of work in Dungeon, Floor and Square

 - Introduce short string and long string in NoMagicHelper.
 - Complete testing of NoMagicHelper.
 - Adds a description for the Dungeon.
 - Allows Dungeon's states "re-writable-lity".
 - Adds the possibility to add and remove a Floor properly in Dungeon (index will be updated).
 - Adds the possibility to get a Floor's reference in Dungeon using Floor's index or Floor's name.
 - Adds the possibility to get a Floor's index in Dungeon using Floor's reference or Floor's name.
 - Adds the possibility to verify if a Floor exist in Dungeon using Floor's index or Floor's name.
 - Smalls updates of Floor and Square, encapsulate completely the Squares in the Floors (Added methods to set and reset Square, and to recover holdable state of the Square in Floor) while the Floor construction is handle solely by Dungeon. Floor methods remains public, and Dungeon is completely public.
 - Beginning testing of Dungeon.

Will come after:
 - Further testing of Dungeon
 - Testing of Floor and Square
 - A graphic editor for Creating a dungeon, add, remove and replace a Floor; set or reset Square
Fifth and final day of work before merging in Dungeon, Floor and Square

- Adds new methods for the Floor class for easiest initialization of Square
- Adds new methods to get a Square from an instance of a Floor
- Adds new methods to verify the initialization of a or all Square in an instance of a Floor
- Some properties are now resetable for Floor and Square : name (Square), description (Floor, Square), holdable (Square)
- Dungeon's testing is done
- Floor's testing is done
- Square's testing is done

Next thing to do:
- A griphic editor for creating a dungeon, etc.