Refactored Everything

- Updated Sample Project Settings (via Xcode).
- Refactored Sample Project view construction (using tidier coding practices).
- Deprecated `-pinEdge:toEdge:ofItem:` methods for more flexible `-pinAttribute:toAttribute:ofItem:` instead.
- Added `-pinAttribute:toAttribute:ofItem:withConstant:relation:` method to replace `-pinEdge:ToEdge:ofItem:inset:relation:`.
- Updated deprecated methods compiler flags to provide message with replacement methods.
- Updated README with instructions on installing and the future of deprecated methods.
- Refactored header to separate deprecated methods into a different interface.
- Refactored header to use full appledoc documentation on all methods.
- Refactored header grouping methods together and reordering them.
- Updated .m file to follow the same order and added `#pragma mark -` to separate methods out. 
- Changed `JRTViewPinEdges` enum from `unsigned long` to `NSUInteger` (to fix an issue with appledoc generation).

I haven't updated the podspec because it might be worth reviewing the documentation beforehand for any typos or grammar issues.

Also, I don't think i've broken anything (the example still works) but it might be worth a quick check!

Liam