Make global inititalization optomizable by closure compiler

The old way of setting the global broke with closure under advanced optimizations.  This method will work without closure still, but with closure if the user adds a `var pluralize;` to their code, closure can optimize the pluralize code/names in a whole-program fashion.
@blakeembrey implicit globals are the most effective, because then closure compiler users can just add the explicit global declaration somewhere in their code, and get everything optimized for them.  So, in our code it's actually an explicit global, but that's not a real option in this case I don't think, since it would pollute in the amd/commonjs case -- well, not pollute very much, but it would define the name at least, instead of leaving it undefined.