Merge pull request #4 from LumiGuide/fixes

Some fixes to the cabal file
Add Event module with handlers for most events
Remove the OnSelectedChange event handler
Prevent <textarea> elements from having children
Update the Todo example to use the new event handlers
Don't do a sync. redraw when the user clicks a checkbox
Document onMouseOver and onMouseOut properly
Pass the absolute scroll position to the onScroll callback
Add the EventTest demo app
Add Text.Blaze.Event.Internal to the cabal file

Otherwise clients of blaze-react fail to load the interface for that module.