Added comment about http_method_override and HttpCache
feature#592 Added comment about http_method_override and HttpCache (kbond)

This PR was merged into the master branch.

Discussion
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Added comment about http_method_override and HttpCache

related: symfony/symfony#8481

Commits
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b6ee002 Added comment about http_method_override and HttpCache
Refactored contact action to use new form methods in 2.3
fixed CS