minor doc fixes
Fixes #1941 reset CHtml:: instad of hardcoded value
send CHtml::errorCss to JS file
added changelog
Merge pull request #1944 from mdomba/1941-CACtiveForm-reset-errorCss

Fixes #1941 cActiveForm form reset
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Fixes #1942 CActiveForm client validation
Merge pull request #1946 from mdomba/1942-CActiveForm-clientvalidation

Fixes #1942 CActiveForm client validation
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