FormHelper should allow model to be inherited from hash

Hi, attached is the failing test. The patch from wildchild make it pass.

Patch updated to require core_ext/array/extract_options.

(from [9cee693213e0205cb5992728bb516215e34cb79f]) Merge branch 'master' of github.com:rails/rails

• 'master' of github.com:rails/rails: (44 commits) Fixed indentation in actionmailer base_test [#6538 state:committed] remove unused assigned variable removes merge conflicts removes Examples headers introduced in 9b96de6 Revert "Fixed identation in actionmailer base_test" Report the correct value of nil.id in the exception message as different ruby implementations may have different values, for example Rubinius returns 53 for nil.id. Improve testing of cookies in functional tests: - cookies can be set using string or symbol keys - cookies are preserved across calls to get, post, etc. - cookie names and values are escaped - cookies can be cleared using @request.cookies.clear more style changes Some style changes style changes Revert "style changes" Raise ArgumentError if route name is invalid [#6517 state:resolved] style changes Allow model to be inherited from Hash [#6487 state:resolved] styles applied for usage added failing test for fields_for with a record object that inherits from Hash Fixed identation in actionmailer base_test wrong SQL statement commas to set off expressions that interrupt sentence flow typo changes ... https://github.com/rails/rails/commit/9cee693213e0205cb5992728bb516...