Clarify association mapping language

- 5.3 was wrong - should really be 'inversedBy'
- 11.1 - change 'use' to 'have' for consistency.  A class has an attribute.

- See https://github.com/doctrine/doctrine2/issues/6686

docs/en/reference/association-mapping.rst

@@ -268,7 +268,7 @@ Generated MySQL Schema:
     ) ENGINE = InnoDB;
     ALTER TABLE Cart ADD FOREIGN KEY (customer_id) REFERENCES Customer(id);
 
-We had a choice of sides on which to place the ``mappedBy`` attribute. Because it
+We had a choice of sides on which to place the ``inversedBy`` attribute. Because it
 is on the ``Cart``, that is the owning side of the relation, and thus holds the
 foreign key.
 

docs/en/reference/unitofwork-associations.rst

@@ -15,10 +15,10 @@ Bidirectional Associations
 
 The following rules apply to **bidirectional** associations:
 
-- The inverse side has to use the ``mappedBy`` attribute of the OneToOne,
+- The inverse side has to have the ``mappedBy`` attribute of the OneToOne,
   OneToMany, or ManyToMany mapping declaration. The mappedBy
   attribute contains the name of the association-field on the owning side.
-- The owning side has to use the ``inversedBy`` attribute of the
+- The owning side has to have the ``inversedBy`` attribute of the
   OneToOne, ManyToOne, or ManyToMany mapping declaration. 
   The inversedBy attribute contains the name of the association-field
   on the inverse-side.