Removes the checkbox of Anisotropic filtering from the GSDX plugin settings, the checkbox was usually used to enable & disable the AF which is not necessary since there is an option in the drop down list for disabling AF.
the internal function value of "AnisotropicFiltering" has been replaced with "MaxAnisotropy" for detection.
the detection uses the function getconfig("MaxAnisotropy", value) where value 0 means disabled and value is the default value when no value is set in the INI file.