Enhancements

• Added the ability to load an existing .xcscheme file and manipulate
  it using Xcodeproj::XCScheme.
  Olivier Halligon
  #288
  • Sorting is now done in a case-insensitive manner.
    Emma Koszinowski
    CocoaPods#3684
• Trailing whitespace is stripped when serializing XCConfig files.
  Samuel Giddins
• XCConfig values that are only $(inherited) will be omitted during
  serialization.
  Samuel Giddins