Fixed crash when stub with very long data and no delay for response
Add missing free call
Fixed crash when stub with very long data and no delay for response (fixes #57 #59)
Tests are now testing against AFNetworking 2.2.3.

Note: Unfortunately we still have to use OCUnit/SenTestKit and can't migrate to XCTest because XCTest requires a deployment target of iOS7+
Storing stub upon the instantiation of OHHTTPStubsProtocol to avoid race conditions (should hopefully fix #51)
Updated README, moved CHANGELOG from wiki to a file, bumped to version 3.1.1
README: Adding Cocoapods version & platform badges + links to the Help Topics / Wiki pages
README: Fixing badges and final tweaks