This commit restructures many of the ES6 modules, splitting them
up to actual export multiple functions instead of a single object.
It also splits up Util into multiple sub-modules, to make it easier
to maintain.
Finally, localisation is renamed to localization.
This removes the special comment part of the ES6 module syntax,
opting to enable ES6 module syntax by default.
It also appends `.js` to all import paths to better support in-browser
loading.
This commit restructures noVNC, splitting it into the core directory
and the app directory, with the former containing core noVNC parts,
and the latter containing parts specific to the application.
