Icon and menu aesthetics

[spencerng]

• Convert the menu icons to LinearLayouts so that they aren't dependent on screen aspect ratio to look correct
  • Some phones are no longer 16:9, leading to a large gap in the middle of the phone main menu layout
  • The game logo is also too big on these phones
• Change the margins of the settings menu so they are consistent across all devices (MeMO tablets, Amazon Fire tablets, various smartphones). Currently, the margins of regular Preference objects have too much left padding on some devices.