CUBRID Database 9.0 Support.
Ref: converted spaces to tabs according to Yii coding conventions.
Ref: converted spaces to tabs.
Merge branch 'cubrid-database-support' of https://github.com/kadishmal/yii into kadishmal-cubrid-database-support

* 'cubrid-database-support' of https://github.com/kadishmal/yii:
  Ref: converted spaces to tabs.
  Ref: converted spaces to tabs according to Yii coding conventions.
  CUBRID Database 9.0 Support.
CUBRID copyright, version and indentation fixes

adjustments to PR #1893
Code style

adjustments to PR #1893
Allow sql files diff & preview in gii
Backport Request::getPreferredLanguage() from yii2
Parameter 'id' added for 'ajaxUpdateError' invoke at 'jquery.yiigridview' and 'jquery.yiilistview'
Doc comments for 'ajaxUpdateError' at 'CGridView' and 'CListView' have been updated.
Issue #2850 added to CHANGELOG
Enh #3225: Add CForm::errorSummaryHeader and CForm::errorSummaryFooter, used like in CActiveForm::errorSummary().
Relocated the line added to CHANGELOG.
Eager loading note added to 'Relational Query Options' docs
CActiveForm::error() fixed to respect 'hideErrorMessage' option on regular output
Issue #3302 added to CHANGELOG
jquery.yiiGridView fixed to be able handling special chars if history is enabled
jquery.yiiListView fixed to be able handling special chars if history is enabled
Issue #3253 added to CHANGELOG
Issue #3253 corrected to #2519 at CHANGELOG