support package and map configuration

When working with the requirejs validator, it seems like it currently ignores the package and map sections : 
http://requirejs.org/docs/api.html#packages
http://requirejs.org/docs/api.html#config-map

I've put together a test repo demonstrating how it works in the browser, yet fails mimosa-require verification :
https://github.com/silver83/mimosa-require-test

I'll try to take a look at how hard it will be for me to create a pr for this.