Improvement of ranges
Improve timer

Delete a useless method and useless lines
Add the dectection of timers and locks when an expression is built
Add a method to init all the timers (to improve later with variables,
actually not implemented)
Correct some bugs, some improvement

- clean correctly the screen and its attributes when a new file is ordered or
  opened
- when saved a '.json' is put at the end of the file if not precised
- some spaces forgotten
Some bugs corrected

- When an arc is created, it is labelled with false instead of False,
  considering the grammar parsiing those labels accept the first one only.
- When an arc has no consequence, the getConsequences method return [] instead
  of ['']
- Add an itertools import a the beginning of the file instead of the method
  using it.
Link the graph editor and the state machine

Make the graph editor compile a state machine and run launching a pygame window
with sprites moving