Update AnnotationsBag.php

Adding the replace method and using it to implement the ArrayAccess interface to AnnotationsBag. Now you can access annotations bags attributes like an array
bug fix the merge method
Update AnnotationsBagTest.php

adding ArrayAccess tests
offsetSet bug fixed
added more Arrayaccess tests
Update AnnotationsBag.php

adding the set method
Update AnnotationsBag.php

bug and documentation fixes for ArrayAccess methods
Update AnnotationsBagTest.php

added tests
Update AnnotationsBag.php
bug fixes and test addition to ArrayAccess interface
Parser update
Update AnnotationsBag.php

documentation update
unit test modification
Merge branch 'desenv' of github.com:nyamsprod/annotations into desenv
Merge pull request #14 from nyamsprod/desenv

Mutable AnnotationsBag