AFNetworking/AFNetworking — pull request #1941 by tsheaff (2014-03-25 00:05:03+00:00)
Title: Add a flag on AFHTTPRequestSerializer to optionally avoid ever requiring the main thread

I have an implementation of integration specs that invokes an instance of `AFHTTPRequestOperation` synchronously using `waitUntilFinished` so that I can make assertions after running a series of calls, each guaranteed to finish before the next begins. Pretty common pattern.

But I had to hunt down why things were timing out whenever I POSTed multipart forms. Any reason why a networking library ever needs to perform anything on the main thread? Would be much cleaner to just remove the `[[NSThread currentThread] isMainThread]` entirely. Things seem to run perfectly with no issues when I simply kill this block.