UMD wrapper didn't work with some AMD build tools

Was trying to include hammer as part of my AMD build and it didn't see it as AMD because exports and module are defined.  Switched the UMD wrapper for one very similar to Lo-Dash's (which works as part of my AMD build).  Also removed the `window.` declaration on define because AMD can be used in other environments.  This changed required adding `define: false` to globals in the Gruntfile.  I also ran `grunt build` to make sure everything was good to go.