[Security] Create a distinct service for each authentication provider

When using multiple both
Make travis pass on Symfony 2.2

Make travis actually update the lock file and install the 2.2 components.
Document deprecation of getClassMetadata in validator docs.
Add symfony/property-access require for 2.2

This gives an actual good version of symfony/form instead of some old beta.
merged branch igorw/2.2-tests (PR #639)

This PR was merged into the master branch.

Commits
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6e8d404 Add symfony/property-access require for 2.2
337a92c Make travis pass on Symfony 2.2

Discussion
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Make travis pass on Symfony 2.2

Make travis actually update the lock file and install the 2.2 components.
Document deprecation of getClassMetadata in validator docs.
merged branch GromNaN/auth-provider (PR #640)

This PR was merged into the master branch.

Commits
-------

fdd89b9 [Security] Create a distinct service for each authentication provider

Discussion
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[Security] Rename authentication_provider services to avoid name conflict

When using both anonymous and form authentication providers, they share the same service name whereas they use totally different classes.

Before : `security.authentication_provider.myfirewall`
After : `security.authentication_provider.myfirewall.dao` and `security.authentication_provider.myfirewall.anonymous`

The naming follows the recommendation for custom auth providers.
http://silex.sensiolabs.org/doc/providers/security.html#defining-a-custom-authentication-provider