Enhance CJSON with JsonSerializable support (#2540)
Encoding a JsonSerializable object will now have it's serializable result
encoded by CJSON.
Added a guard to prevent the autoload bug as mentioned by @cebe.
Added unit test.
Translated
* framework/views/
* framework/messages/
* requirements/views/
* requirements/messages/
Gii model generator template updated to escape single quotes in the labels.
Issue #2876 added to CHANGELOG
Merge pull request #2879 from klimov-paul/2876-gii-model-generator-label

Fixes #2876 gii model generator label escaping single quotes
Missing author for fix #2874 added to CHANGELOG
Merge pull request #2878 from Theill11/DK-translations

Added danish translations
Fixed spelling, punctuation and whitespace
Merge pull request #2882 from Theill11/update-danish-translations

Fixed spelling, punctuation and whitespace
fixed code style
2887 Add __isset method for CFormElement
Fix indention from spaces to tabs in CFormElement
Add bug #2887 to CHANGELOG
updated phpdoc and input types list in CFormInputElement
Merge pull request #2896 from gureedo/form-update

updated phpdoc and input types list in CFormInputElement
Add Norwegian translation messages for zii.php
Merge pull request #2897 from atmoz/master

Add Norwegian translation messages for zii.php