Use the widget objects for textarea.

Use widgets instead of templates directly.
Merge pull request #2883 from cakephp/3.0-textarea-fix

Use the widget objects for textarea.
Added the letter s to a comment.
Removed 4 lines of useless code.
Merge pull request #2884 from sam-at-github/controller-tidy

Controller tidy
Make the wannabe fully qualified namespaces in docblock tags actually fully qualified by adding leading backslashes.
Resolves #2870
Fix docblock tag namespace that slipped through because the tag was incorrectly named @throw instead of @throws. Fixed the tag name too and also added missing sub-namespace.
Fix malformed/missing @throws docblock tags (split into multiple tags, add missing leading backslashes and sub-namespaces, etc)
Remove unnecessary @return tags in constructor and deconstructor docblocks.
Fix docblock/function signature mismatches (parameter name typos, wrong parameter types, missing parameter tags, invalid/wrong/missing return types, missing/unnecessary leading backslashes for namespaces, etc...)
Revert splitting up `@throws` tag as CS doesn't like it.
Explicitly add `@param` tags for overwritten methods instead of
relying on inheritance.
Re-add some docblock-tag namespace fixes that got lost due to rebasing
Merge pull request #2882 from ndm2/3.0-docblock-updates

3.0 - Docblock updates
Add test case for FormHelper::checkbox().
Remove unused properties and methods.
Use _secureFieldName().
Merge pull request #2886 from ADmad/3.0-formhelper

3.0 formhelper
Start to unskip datetime tests.
Fix up some limits that go funny when FormHelper starts using DateTime.