do not check content-type twice in sendFile() method
Merge pull request #783 from mnlg/content-type

Do not check content-type twice in sendFile() method
Let Slim request and response objects use Guzzle\Stream
Clean up test output
Fix merge conflicts
Fix docblocks in \Slim\Http\Request
Update docblocks in \Slim\Http\Request
Update docblocks in \Slim\Http\Headers
Update docblocks in Slim/Http/Cookies
Add Guzzle Stream files directly to repo as suggested by Michael Dowling
Update \Slim\Http\Response unit tests
Refactor Slim\Http\Response
merge dev-codeguy