Change the ways global variable names and output names work

Expected Behavior / Situation

When I define a bundle and name it xyz.abc, I expect the bundle to be registered under window['xyz.abc'].

Actual Behavior / Situation

This is what happens instead: window.xyz.abc. Same for globals. Consider this:

globals: {
  '@namespace/package': 'namespace.package
}

This becomes window.namespace.package, instead of window['namespace.package'].

Modification Proposal

Defining name: 'namespace.package' should be compiled to window['namespace.packge']. Defining name: ['namespace', 'package'] could allow specifing the keypath, resulting in window.namespace.package.