restricted the HTTP fragment service provider to Symfony 2.4+
made cookbook titles more consistent
bug #832 restricted the HTTP fragment service provider to Symfony 2.4+ (fabpot)

This PR was merged into the master branch.

Discussion
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restricted the HTTP fragment service provider to Symfony 2.4+

The HTTP fragment service provider cannot work on Symfony 2.3+ (see #819)

Commits
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c2fa4cb restricted the HTTP fragment service provider to Symfony 2.4+