Naming conflict always sets Wkt to undefined in some browsers.

The naming conflict caused by "var Wkt = Wkt || require('./wicket')" would assign the local variable to itself rather than using the global.  Since the local is undefined by default, this would always lead to the latter branch and call the require.

We unfortunately  need to support browsers like IE 8.  This is the only change we had to make to get it to work properly.