Handle Icon Image Load Failure

[SkylerBurger]

As a user, when an icon's image fails to load, I'd like to see a default image that notifies me of the lack of response from the image link while not blocking the loading of the Dialer view.

• [x] Select a default "missing icon" image or icon, possibly grab something from FontAwesome
• When an icon image fails to load or returns an error:
  • [x] Present the default image in that icon's location
  • [x] Increment the load counter in order for the Dialer to fade-in
  • [x] Do not cache a failed/error response for the image icon in order to allow the app to retry upon each refresh
  • It may be worth reviewing this cache pattern to see if it is recommended or "smelly".

[SkylerBurger]

This Issue was addressed in PR #78