Add RESTful method support for html forms

This commit allows calls to `CHtml::form()`, `CHtml::beginForm`
`CActiveForm::$method` etc to accept verbs other than `post` and `get`,
e.g. `delete`, `put`, `patch` etc

This is implemented by detecting non `post`, `get`, converting to `post`
 and adding a hidden `_method` field, similar to how CSRF protection works.
update changelog
add absolutePaths option to CFileHelper::findFiles

if absolutePaths is true (by default), function will return absolute paths, otherwise the relative ones
mbstring fallback for CFileHelper::findFiles
framework/messages/ja/yii.php updated
Merge pull request #2725 from softark/ja-update-2013-08-03

framework/messages/ja/yii.php updated
Add alias to imports when returning

addition to #2723 fixing issue #2642
Changed header case Content-type to Content-Type

fixes #2709 fixes #2726
Better fix for #2642

changes made after discussion in #2723
Update finnish translations
Merge pull request #2730 from janisto/messages_fi_update-5

Update finnish translations
ru: updated docs
ru: typo fixes
update german translation
Merge pull request #2731 from cebe/german-translation

update german translation
[UK] Updating docs
Merge pull request #2735 from yiiframework-com-ua/uk_docs

[UK] Updating docs
Added closing parentheses to verifyPassword instruction
Merge pull request #2743 from jpopesculian/patch-1

Added closing parentheses to verifyPassword instruction
[UK] Blog and guide updates