modified syntax.mli
modified lexer.mll
old syntax.mli
add graph.ml
 call graph for expression test
Merge branch 'master' of github.com:MaximeHeckel/ico-project

* 'master' of github.com:MaximeHeckel/ico-project:
  type_expr
  add ssarbredroit and ssarbregauche function
  add map and same type function
  add tree.ml
  add tree.ml
  Type arbre polymorphe
  commit before pull
  add parser.mly test new pseudopascal.mly