Added apidoc for \KsUtils\Pager class
Added apidoc for \KsUtils\Pager class
Formatted code for PSR-2 style in  \KsUtils\Pager class
Added apidoc for \KsUtils\StrFilter interface
Added apidoc for \KsUtils\StrFilter interface and applying code style
Added apidoc for \KsUtils\Validator class