Removed reliance on `stringWithUTF8String:`
The current method relies on
(1) @("foo") calling through to stringWithUTF8String:. This relies on both runtime and compile time details that are subject to change.
(2) Swizzling out stringWithUTF8String:.

These hacks can be removed in favor of direct dispatch.
remove unnecessary reliance on impl details of blocks
- Changed to objectForLiteralString:
- Made objectForLiteralString: an instance method
- Can now make prefixMapping and suffixMapping private
- Add doc to objectForLiteralString:
Merge branch 'master' of https://github.com/kongtomorrow/OCUDL into kongtomorrow-master

Conflicts:
	Classes/OCUDL.h
	Classes/OCUDLManager.h
	Classes/OCUDLManager.m
Updating readme to note the removal of method swizzling