Changed module index files to prepend '_' instead of appending it

Also made util.object, util.array, and util.string top-level modules
Improved build script to generate a merged declaration file
Renamed WrappedEvent ->EnhancedEvent
Fixed testing code for new module names
Added IEnhancedElement interface for elements that have been augmented with the methods in ElementUtils
Renamed event/Keys -> util/Keyboard and added entire range of possible keys
Fixed imports for recent refactoring
Typed all HTML methods and added new HTML5 elements