Fixes #2906: Added support for using conditional comments for js and css files registered through asset bundles and Html helper

$_SERVER['SERVER_PROTOCOL'] returns 'HTTP/1.0' or 'HTTP/1.1'

issue #3143

Adjustments code according to the standards.
Adding missing PHPDoc comment.

fixes #3028

Improved action filter and action execution flow by supporting installing action filters at controller, module and application levels

Added support to allow an event handler to be inserted at the beginning of the existing event handler list

Fixes #2955: Changed the signature of ActiveQuery constructors and `ActiveRecord::createQuery()` to simplify customizing ActiveQuery classes