Update 2-integration-with-fosuserbundle.md

Annotations so certain IDEs will not complain about unknown methods (PHPStorm for me) and added a $userProvider which is suggested by the UserManager class because userManager->supportsClass() is deprecated on the userManager and suggests to use UserProvider.

I changed the annotation of $facebook based on the argument in config.yml it points to the fos_facebook.api service which is the class I put above.
Merge pull request #313 from tvl83/patch-2

Update 2-integration-with-fosuserbundle.md
Update 2-integration-with-fosuserbundle.md

These are changes I think will help the new comer to the FOSFacebookBundle. I have been working with it all day and found that these settings work.

I also fixed the indention of the previous pull request I submitted.
Merge pull request #315 from tvl83/patch-3

Update 2-integration-with-fosuserbundle.md