Added "security.hide_user_not_found" support in SecurityServiceProvider
feature #772 Added "security.hide_user_not_found" support in SecurityServiceProvider (tomaszsobczak)

This PR was squashed before being merged into the master branch (closes #772).

Discussion
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Added "security.hide_user_not_found" support in SecurityServiceProvider

Added "security.hide_user_not_found" support in SecurityServiceProvider to make configuration similar with Symfony2 framework.

Commits
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9c614f5 Added "security.hide_user_not_found" support in SecurityServiceProvider