Modern Objective C: Fewer brackets

Update Project files for Xcode 7

Adopt more modern objective C

Remove legacy comments

Update Test Xcode project and interface files to 6.4

Update Example Xcode project and interface files for 6.4

Fix warning on viewDidUnload, deprecated iOS 6.0.

More uses of instancetype for initWithFrame

Use instancetype for initWithFrame

Fixed API, make minimumFrameSize property readonly

Using NS_ENUM for better autocompletion

Minor updates to example project

Removed method declarations from private interface

Removed explicit synthesized private member vars

Update .travis.yml