Fix CopyPhase for some missing Public Headers on the project (does not affect users using CocoaPods but only users generating the lib manually)
README suggests `pod install` instead of `update`

`pod update` will also update all the other installed Pods to their latest version, potentially breaking things. `pod install` will just add the new pod.

(Not a huge deal, just seemed like a safer choice)
Merge pull request #55 from MaxGabriel/patch-1

Fixed README : suggest `pod install` instead of `update`
Some README fixes :
 - CocoaPods no longer generates the docset automatically
 - Some presentation fixes to better fit github's markdown
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