Update many comments.
Adjust 'Loader.makePaths' to allow for paths relative to included files.
Remove 'Loader.rebuild' stub, and replace with 'Loader.next' stub.
Add 'Script' tag creation/destruction code.
Add 'Script' event binding/unbinding.
Adjust 'Script' factory functions to take 'Loader' as last parameter.
Default 'Script' factories to use default 'Loader' when omitted.
Add 'Module.install' function to add *magic* global module/exports.
Add 'Module.install' to initialisation.
Set first 'Loader' instance as default in initialisation.