premier commit branche mutation

.../java/avatartranslator/mutation/AddAttributeMutation.java

src/main/java/avatartranslator/mutation/AddMutation.java

...ain/java/avatartranslator/mutation/AttributeMutation.java

src/main/java/avatartranslator/mutation/AvatarMutation.java

...n/java/avatartranslator/mutation/BlockStructMutation.java

...n/java/avatartranslator/mutation/MdAttributeMutation.java

src/main/java/avatartranslator/mutation/MdMutation.java

...n/java/avatartranslator/mutation/RmAttributeMutation.java

src/main/java/avatartranslator/mutation/RmMutation.java

...l/src/test/java/avatartranslator/AvatarMutationTests.java