Add support for logging request & responses during test execution via the `AFTestsLoggingEnabled` environment variable
Add test coverage and fix for "Stream XXX is sending an event before being opened" during multi-part file uploads. fixes #948
Merge branch 'bugfix/948-stream-event-bug' of git://github.com/blakewatters/AFNetworking into blakewatters-bugfix/948-stream-event-bug

Conflicts:
	Tests/AFHTTPClientTests.m
Change double delayInSeconds to NSTimeInterval delay
Minor reformatting
Minor reformatting
Removing abide.jpg in favor of re-using existing Icon.png to test multipart file upload