Merge pull request #291 from Danack/upstream

Moved decision of whether to sign post fields to a function.
Fixing how errors are aggregated when sending multi transfers. Adding isRedirect() flag to requests.
Why, Travis?
Updating CHANGELOG
Removing requirement on PHP 5.3.7 for checking ResponseClassInterface. Closes #293
Adding more information to the error when the phar cacert cannot be copied
Using a relative path for extracting the cacert so that Guzzle can be embedded in third-party phar files.
Preparing to release 3.4.0
Removing special check for 'oauth_token' now that the check against FALSE has been removed.
Adding oauth_verifier as required by OAuth 1.0a.
Adding oauth_callback to signature.
Merge pull request #294 from fubhy/master

Adjustments for OAuth 1.0a
Trying to ucfirst a command when using the service description command factory
Adding support for CurlFile in PHP 5.5. Closes #296.
Fixing how names are added to models. Closes #298
Removing all the popsicle sticks from sending requests with curl_multi
Rethrowing redirect exceptions when a response is not available
Adding events back to CurlMulti and proxying all events
Adding test to ensure events are proxied
Preparing for 3.4.1