Fix PHPDoc
[Guzzle3] Rely directly on url for generating the exception
[Stream] Only seek if the stream is seekable
[StringStream] Rely directly on the casted string to get the size
[Zend1] Fix default client instantiation
[Curl] Refactor detection of the loaded extension
[Fopen/FileGetContents] Refactor to reduce code duplication
Fix tests when guzzle 4 is not installed
[Guzzle] Fix inheritance
Add timeout support