Merge branch 'hotfix/16'

Close #16
Made acceptFilter static and updated references by changing $this->acceptFilter to self::$acceptFilter.  This addresses (hopefully) issue #17, which is caused because onRender(), which is static, tries to use acceptFilter as if its in the context of an object.
Updated variable declaration to keep static AFTER visibility.
Merge pull request #18 from telkins/develop

Made acceptFilter static and updated references...
Merge branch 'hotfix/18' into develop

Forward port #18