ZF-2280: "namespace" is a reserved keyword in PHP 5.3


Zend_Filter_Input uses the keyword "namespace" for its constants NAMESPACE. Since PHP 5.3 "namespace" is reserverd.


Replaces Zend_Filter_Input::NAMESPACE with Zend_Filter_Input::INPUT_NAMESPACE

Adding info to get this fixed by 1.5.

Fixed for next minor release with SVN r7923.

Resolved for next mini-release with SVN r7925.

Updated documentation with SVN r8820.