Adding HTTP Message initializers to OHHTTPStubsResponse

I.e.
+[OHHTTPStubsResponse responseWithHTTPMessageData:
                                     responseTime:]
+[OHHTTPStubsResponse responseNamed:
                         fromBundle:
                       responseTime:]
Merge pull request #27 from nxtbgthng/http-message-response

Adding HTTP Message initializers to OHHTTPStubsResponse
Merge pull request #23 from hborders/redirect

Added redirect support.
Merge pull request #18 from hborders/ignores

Ignored .DS_Store globally.
Removed non-ARC support.
(OHHTTPStubs is intended to be compiled in a separate xcodeproj or integrated with CocoaPods anyway)
improved Thread-safety for requestHandlers (thanks to @hborders / #21)
Stop sending messages to NSURLProtoclClient after -stopLoading (#25)
Simplified API.
Added API Documentation
Updated README for the new 2.0 API
Fixed execute_after now using dedicated queue (Otherwise we have a deadlock on mainQueue, detected thanks to my Unit Tests)
Removed private API (#16), added protection against cached responses (#15).
Fixed execute_after now using dedicated queue (Otherwise we have a deadlock on mainQueue, detected thanks to my Unit Tests)
Introducing new API 2.0
Fixed some header doc
New API 2.0 ready
Allow users to execute responses arbitrarily.

Instead of relying on a timeout, users can now execute responses arbitrarily. An OHHTTPStubsResponse has a responder block, which if populated is called with a dispatch_block_t, which can be called from anywhere to cause processing to continue. This makes ordered operations much easier to guarantee, and will make tests execute faster.