Better replacement of types in expressions and unification with declared type (close #29)

...es/nperier/minichamo/language/definition/FunctionDef.java

...rennes/nperier/minichamo/language/definition/TypeDef.java

...ennes/nperier/minichamo/language/definition/ValueDef.java

...es/nperier/minichamo/language/definition/VariableDef.java

...r/minichamo/language/expressions/ConditionExpression.java

...es/nperier/minichamo/language/expressions/Expression.java

...perier/minichamo/language/expressions/NameExpression.java

...nperier/minichamo/language/expressions/VarExpression.java

...r/minichamo/language/expressions/base/BaseExpression.java

...guage/expressions/visitor/DuplicateExpressionVisitor.java

...mo/language/expressions/visitor/ExpressionArgVisitor.java

...chamo/language/expressions/visitor/ExpressionVisitor.java

...nichamo/language/expressions/visitor/GetNamesVisitor.java

.../language/expressions/visitor/TypeReplacementVisitor.java

...fr/insarennes/nperier/minichamo/language/typing/Type.java