Extract d'un listener (commit pour pull)
Merge branch 'master' of https://github.com/jeanbaptistedalle/scaling-adventure
Correction de code, sécurisation contre les thread des getInstance
Merge branch 'master' of https://github.com/jeanbaptistedalle/scaling-adventure

Conflicts:
	src/dessin/collaboratif/misc/GeneralVariables.java
	src/dessin/collaboratif/model/shape/Shape.java