Add podspec, fix Sample project, modern syntax

- added Podspec
- changed README to markdown, added sample image to repo

MAConfirmButton
- style fixes
- removed @synthesize statements

Sample Project
- removed all XIB files from sample project
- removed prefix file
- updated Info.plist
- added launch screen XIB to allow sample project to run on any screen size
- now runs correctly in Xcode 6 / iOS 8
- updated build settings to recommended
- added icons, asset catalog