Tile transtitions analyser must be robust to faulty tiles

[DjThunder]

Currently, the transitions extraction made since #166 works well only if analyzed map are bug free.
As it learns by checking all existing transitions and constraints for each neighbor, it analyzed map contains faulty tiles, it will provide a wrong result.

By performing a statistic analysis, find out which tiles can be considered as faulty.

In addition, display them on the editor with a red box over it to inform suspicion.
Finally, provide an automatic map fixer, which will backup the old level rip and save the fixed one, which will be used for the real analysis, hopefully bug free.

Note: An easy way to detect faulty tile is to perform a weighted counter for each transition, and remove the one which sounds to be exceptional (or at least less than the average), especially for CENTER tiles which must never be in other transition's type.
Of course, if the average tiles transition are faulty... it will remove only the good one ! But this is the worst case, so the level rip can be considered as broken.