Replace dojo.safeMixin refs with declare.safeMixin
Replace dojo.safeMixin refs with declare.safeMixin

Made possible by http://bugs.dojotoolkit.org/changeset/26259

maier49/dgrid,maier49/dgrid,dylans/dgrid,maier49/dgrid,dylans/dgrid,dylans/dgrid,kfranqueiro/dgrid,kfranqueiro/dgrid,kfranqueiro/dgrid