Splash Screen wrapper service and other stuff

@IanMayo Please check 

I created 2 constants there www/js/app/app.js
```
.constant('SPLASH_ON_LOGIN', true)
.constant('SPLASH_ON_MAIN', false)
```

You can play with them to test how splash screen works on different pages.
Ian's learning time now...

@alexnodejs - why did you decide that these methods should return a boolean value?

If they returned "self" then they could be daisy chained, but I can't see when/why you would use the return value from block()