in the AMD case, reveal the global right away

This is to accomodate synchronous code that might be running alongside AMD modules.  The AMD case already exposes the window.Raven global, however previous to this patch it waited until the AMD module was specified as a dependency before initializing the global.

I figure that if the global is going to be exposed in the AMD case, it
may as well happen right away, so non-AMD code can depend on it being
there. :)