Refactor code to make it more readable
Backwards incompatible changes to delegate methods
Bug fixes, typos, and cleanup
Merge branch 'master' of https://github.com/lukescott/LXReorderableCollectionViewFlowLayout into feature/lukescott-refactoring/14

Conflicts:
	LXReorderableCollectionViewFlowLayout/LXReorderableCollectionViewFlowLayout.m
	README.md
Changing coding convention of LXS_CGPointAdd function.
- Introduces LXScrollingDirectionUnknown.
- Following Cocoa convention about extending a Cocoa framework class. https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/CodingGuidelines/Articles/NamingMethods.html%23//apple_ref/doc/uid/20001282-1003829-BCIBDJCA
- Refactored pull request #14.
- Return longPressGestureRecognizer and panGestureRecognizer to weak attributes.
- Keep in sync to the issue reported in #16: Although I'm not very sure about the issue, it is pretty good practice to be conscious about the retaining of self and checking against it.