support for the epubReadingSystem object

Note that I have not executed the Rake build, so the source files in the "development" and "release" folders, as well as inside each individual module's "lib" folder, are not up to date.

Also note that I have not tested "reflowable_view.html" and "fixed_view.html", which should now display the epubReadingSystem object in the Javascript console.

Finally, note that epubReadingSystem.name = "Readium.js" and epubReadingSystem.version = "0.0.1" ... feel free to adjust accordingly ;)