This commit requires the loader bridge code to implement a "register" function.
The purpose of register() is to hot-load predefined modules. For example, in
an AMD system, you can use the global define() method to set up Atomic and
Atomic/Component to load automatically on the first call to Atomic.load().

By default, Atomic.loader.register will write directly to Atomic._.modules
until it has been overridden.