Add a pre-player / parent screen

[llucax]

When the app is opened, instead of going straight to the player, there should be a parent screen. This screen should contain at least the following (in the long term):

• Legal information

  • Terms of service
  • Privacy
  • Open source licenses
  • Content licenses and attributions if content is shipped as assets or for the currently loaded bundle

• Bundle load screen

  • From the filesystem
  • From the internet (URL or some sort of index/app store)
  • Should show content licenses and attributions

• Links to support the development