Changes Compiler flag

Changes -Weverything to -Wall because -Weverything is a bit aggressive
Fixes header search paths for example project

The example project was searching one directory to high for the API
Change ENUM declarations

Changes the typedef'ed enums to use the NS_ENUM and NS_OPTIONS macros to provide the compiler with better information.
These will work fine on iOS 5 and lower since they are compile time macros but it does mean that the app must be built with the iOS 6 SDK.
Merge pull request #9 from 500px/Issue-#8-Warnings

Issue #8 warnings